feat(policies): capture the full premium breakdown

The capture form only ever had prima neta, derecho de póliza and comisión.
The Access form it replaces has seven figures, and the four that were missing
are the ones that make a policy paid in installments add up.

Adds recargo, IVA, prima total and forma de pago to the policy header, the
same breakdown per installment, and a per-line-of-business IVA rate.

IVA and prima total are the only derived figures:

    base  = prima neta + recargo + derecho de póliza
    IVA   = round(base * tasa)
    total = base + IVA

The recargo is inside the taxable base. That is not a guess — policy 7006785
prints IVA 52.03 on 610.86 + 8.55 + 31.00, and leaving the recargo out gives
51.35, which matches nothing on the page. Both of its money rows are asserted
in premium.spec.ts. The recargo itself is never derived: the carrier quotes it,
so staff key it in, and the field is disabled on ANNUAL/SINGLE. Both derived
figures are stored rather than recomputed on read, and stay editable, because
the printed policy is the record of truth and a later rate change must not
silently restate what was issued.

The rate lives on PolicyType (seeded to 0.08, editable in Catálogos), which is
the legacy one-row IMPUESTOS / IMPUESTOS_AUTOS tables made configurable. The
rate applied is stamped on the policy so an old one reads back at its original
rate.

Per-installment, not two fixed slots on the header: a policy split into several
exhibiciones prices each payment separately — that is why the Access form drew
the money row twice — and a trimestral policy needs four, which the Access
layout could not hold.

Also fixes two losses in the ETL, which is how these went missing:

  - `forma_pago` was marked consumed by the coverage sweep and then never
    written to any column, so FORMA PAGO existed nowhere in the platform.
  - `recargo` and the whole second money row fell into `coveragesJson` as
    loose strings, mislabeled as coverage amounts.

transform_policies.py now writes all of it directly;
backfill_policy_premium_breakdown.py recovers it on a database that must not be
re-imported, and strips the migrated keys back out of coveragesJson. Both are
COALESCE-only, so a figure a human has corrected in the app wins.

IVA and TOTAL are NOT backfilled: they were unbound calculated controls on the
Access form, never columns, so there is nothing to recover and every migrated
policy reads null until it is edited.

The backfill warns on 5 annual policies that carry a non-zero recargo — a
contradiction that predates this change and is left for a human, not silently
corrected.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

apps/api/src/policies/children.dto.ts

@@ -12,6 +12,10 @@ import { Currency } from "@jorgecuadros/database";
 // Each child DTO covers create; updates reuse the same shape with all fields
 // optional via the corresponding Update class. Route supplies the policyId.
 
+// A policy split into several exhibiciones prices each payment on its own —
+// the Access form printed the whole money row once per pago — so the premium
+// breakdown repeats here. `amount` remains what was actually collected and is
+// never recomputed from the breakdown; the two differ by rounding in the books.
 export class InstallmentDto {
   @IsInt() sequence!: number;
   @IsOptional() @IsNumber() amount?: number;
@@ -20,6 +24,13 @@ export class InstallmentDto {
   @IsOptional() @IsString() paidDate?: string;
   @IsOptional() @IsString() checkNumber?: string;
   @IsOptional() @IsBoolean() isCash?: boolean;
+  @IsOptional() @IsNumber() netPremium?: number;
+  @IsOptional() @IsNumber() surcharge?: number;
+  @IsOptional() @IsNumber() policyFee?: number;
+  @IsOptional() @IsNumber() tax?: number;
+  @IsOptional() @IsNumber() taxRate?: number;
+  @IsOptional() @IsNumber() total?: number;
+  @IsOptional() @IsNumber() commission?: number;
 }
 export class UpdateInstallmentDto {
   @IsOptional() @IsInt() sequence?: number;
@@ -29,6 +40,13 @@ export class UpdateInstallmentDto {
   @IsOptional() @IsString() paidDate?: string;
   @IsOptional() @IsString() checkNumber?: string;
   @IsOptional() @IsBoolean() isCash?: boolean;
+  @IsOptional() @IsNumber() netPremium?: number;
+  @IsOptional() @IsNumber() surcharge?: number;
+  @IsOptional() @IsNumber() policyFee?: number;
+  @IsOptional() @IsNumber() tax?: number;
+  @IsOptional() @IsNumber() taxRate?: number;
+  @IsOptional() @IsNumber() total?: number;
+  @IsOptional() @IsNumber() commission?: number;
 }
 
 export class VehicleDto {

apps/api/src/policies/lookup.dto.ts

@@ -1,4 +1,4 @@
-import { IsOptional, IsString, MinLength } from "class-validator";
+import { IsNumber, IsOptional, IsString, Max, Min, MinLength } from "class-validator";
 
 export class ProviderDto {
   @IsString() @MinLength(1) name!: string;
@@ -7,13 +7,19 @@ export class UpdateProviderDto {
   @IsOptional() @IsString() @MinLength(1) name?: string;
 }
 
+// `taxRate` is the IVA fraction for this line of business (0.08 = 8%), the
+// legacy one-row IMPUESTOS / IMPUESTOS_AUTOS tables made editable. Bounded at
+// 1 because a rate is a fraction, not a percentage: 8 entered here would tax a
+// $600 premium $4,800, and the mistake is easy to make.
 export class PolicyTypeDto {
   @IsString() @MinLength(1) name!: string;
   @IsOptional() @IsString() shortDescription?: string;
+  @IsOptional() @IsNumber() @Min(0) @Max(1) taxRate?: number;
 }
 export class UpdatePolicyTypeDto {
   @IsOptional() @IsString() @MinLength(1) name?: string;
   @IsOptional() @IsString() shortDescription?: string;
+  @IsOptional() @IsNumber() @Min(0) @Max(1) taxRate?: number;
 }
 
 export class AdjusterDto {

apps/api/src/policies/policies.service.ts

@@ -250,7 +250,16 @@ export class PoliciesService {
     const [types, providers] = await this.prisma.$transaction([
       this.prisma.policyType.findMany({
         orderBy: { name: "asc" },
-        select: { id: true, name: true, _count: { select: { policies: true } } },
+        select: {
+          id: true,
+          name: true,
+          shortDescription: true,
+          // The capture form computes IVA client-side as the operator types,
+          // so the rate has to travel with the type list it already loads —
+          // an extra round-trip per keystroke is not an option.
+          taxRate: true,
+          _count: { select: { policies: true } },
+        },
       }),
       this.prisma.insuranceProvider.findMany({
         orderBy: { name: "asc" },
@@ -259,7 +268,13 @@ export class PoliciesService {
     ]);
 
     return {
-      types: types.map((t) => ({ id: t.id, name: t.name, count: t._count.policies })),
+      types: types.map((t) => ({
+        id: t.id,
+        name: t.name,
+        shortDescription: t.shortDescription,
+        taxRate: t.taxRate,
+        count: t._count.policies,
+      })),
       providers: providers.map((p) => ({
         id: p.id,
         name: p.name,
@@ -397,6 +412,13 @@ export class PoliciesService {
         paidDate: toDate(dto.paidDate) ?? undefined,
         checkNumber: dto.checkNumber,
         isCash: dto.isCash,
+        netPremium: dto.netPremium,
+        surcharge: dto.surcharge,
+        policyFee: dto.policyFee,
+        tax: dto.tax,
+        taxRate: dto.taxRate,
+        total: dto.total,
+        commission: dto.commission,
       },
     });
   }
@@ -412,6 +434,13 @@ export class PoliciesService {
         ...(dto.paidDate !== undefined && { paidDate: toDate(dto.paidDate) }),
         checkNumber: dto.checkNumber,
         isCash: dto.isCash,
+        netPremium: dto.netPremium,
+        surcharge: dto.surcharge,
+        policyFee: dto.policyFee,
+        tax: dto.tax,
+        taxRate: dto.taxRate,
+        total: dto.total,
+        commission: dto.commission,
       },
     });
   }

apps/api/src/policies/policy.dto.ts

@@ -6,12 +6,16 @@ import {
   IsString,
   MinLength,
 } from "class-validator";
-import { Currency } from "@jorgecuadros/database";
+import { Currency, PaymentFrequency } from "@jorgecuadros/database";
 import { IsEnum } from "class-validator";
 
 /** Editable policy-header fields. coveragesJson (freeform legacy blob) is not
  *  exposed for editing. Dates arrive as ISO strings and are coerced by the
- *  service. `total` is legacy-dead data — the UI uses netPremium. */
+ *  service. `total` is legacy-dead data on migrated rows — list and sort code
+ *  still uses netPremium — but the capture form writes it going forward, along
+ *  with `tax`, from the arithmetic in premium.ts. Both arrive as plain numbers
+ *  rather than being recomputed server-side: the printed policy is the record
+ *  of truth and staff must be able to key its rounding verbatim. */
 export class CreatePolicyDto {
   @IsString() @MinLength(1) policyNumber!: string;
   @IsString() @MinLength(1) customerId!: string;
@@ -24,10 +28,14 @@ export class CreatePolicyDto {
   @IsOptional() @IsString() policyTo?: string;
   @IsOptional() @IsInt() coveragePeriodDays?: number;
   @IsOptional() @IsNumber() netPremium?: number;
+  @IsOptional() @IsNumber() surcharge?: number;
   @IsOptional() @IsNumber() policyFee?: number;
   @IsOptional() @IsNumber() brokerFee?: number;
   @IsOptional() @IsNumber() commission?: number;
+  @IsOptional() @IsNumber() tax?: number;
+  @IsOptional() @IsNumber() taxRate?: number;
   @IsOptional() @IsNumber() total?: number;
+  @IsOptional() @IsEnum(PaymentFrequency) paymentFrequency?: PaymentFrequency;
   @IsOptional() @IsEnum(Currency) currency?: Currency;
   @IsOptional() @IsString() observations?: string;
   @IsOptional() @IsString() notes?: string;
@@ -48,10 +56,14 @@ export class UpdatePolicyDto {
   @IsOptional() @IsString() policyTo?: string;
   @IsOptional() @IsInt() coveragePeriodDays?: number;
   @IsOptional() @IsNumber() netPremium?: number;
+  @IsOptional() @IsNumber() surcharge?: number;
   @IsOptional() @IsNumber() policyFee?: number;
   @IsOptional() @IsNumber() brokerFee?: number;
   @IsOptional() @IsNumber() commission?: number;
+  @IsOptional() @IsNumber() tax?: number;
+  @IsOptional() @IsNumber() taxRate?: number;
   @IsOptional() @IsNumber() total?: number;
+  @IsOptional() @IsEnum(PaymentFrequency) paymentFrequency?: PaymentFrequency;
   @IsOptional() @IsEnum(Currency) currency?: Currency;
   @IsOptional() @IsString() observations?: string;
   @IsOptional() @IsString() notes?: string;

apps/api/src/policies/premium.spec.ts

@@ -0,0 +1,90 @@
+import {
+  DEFAULT_TAX_RATE,
+  computeTax,
+  computeTotal,
+  resolveTaxRate,
+  surchargeApplies,
+  taxableBase,
+} from "./premium";
+
+/**
+ * The reference case is policy 7006785 (MULT, semestral, GMX, two payments) as
+ * it stands in the Access books — the screen Jorge sent. Both of its money
+ * rows are asserted, because the second one is the case that proves the
+ * surcharge belongs in the taxable base and that a zero policy fee is a real
+ * value rather than a missing one.
+ */
+describe("premium arithmetic", () => {
+  it("matches the first payment of policy 7006785", () => {
+    const parts = { netPremium: 610.86, surcharge: 8.55, policyFee: 31.0 };
+    expect(taxableBase(parts)).toBe(650.41);
+    expect(computeTax(parts, 0.08)).toBe(52.03);
+    expect(computeTotal(parts, 0.08)).toBe(702.44);
+  });
+
+  it("matches the second payment of policy 7006785", () => {
+    const parts = { netPremium: 589.71, surcharge: 8.26, policyFee: 0 };
+    expect(computeTax(parts, 0.08)).toBe(47.84);
+    expect(computeTotal(parts, 0.08)).toBe(645.81);
+  });
+
+  it("excluding the surcharge does NOT reconcile", () => {
+    // Guards the one decision in this module that is easy to get wrong: the
+    // spoken-language version of the rule ("prima neta + derecho * 8%") gives
+    // 51.35, and the printed policy says 52.03.
+    const withoutSurcharge = { netPremium: 610.86, surcharge: 0, policyFee: 31.0 };
+    expect(computeTax(withoutSurcharge, 0.08)).not.toBe(52.03);
+  });
+
+  it("treats blank and null money as zero, not NaN", () => {
+    expect(taxableBase({ netPremium: "610.86", surcharge: null, policyFee: "" })).toBe(
+      610.86,
+    );
+    expect(computeTax({ netPremium: undefined, surcharge: null, policyFee: null }, 0.08))
+      .toBe(0);
+  });
+
+  it("rounds half-up to cents", () => {
+    // 100.06 * 0.08 = 8.0048 -> 8.00; 100.13 * 0.08 = 8.0104 -> 8.01.
+    expect(computeTax({ netPremium: 100.06, surcharge: 0, policyFee: 0 }, 0.08)).toBe(8);
+    expect(computeTax({ netPremium: 100.13, surcharge: 0, policyFee: 0 }, 0.08)).toBe(8.01);
+  });
+
+  describe("surchargeApplies", () => {
+    it("is false for the two single-payment frequencies", () => {
+      expect(surchargeApplies("ANNUAL")).toBe(false);
+      expect(surchargeApplies("SINGLE")).toBe(false);
+    });
+    it("is true for every split frequency", () => {
+      expect(surchargeApplies("SEMIANNUAL")).toBe(true);
+      expect(surchargeApplies("QUARTERLY")).toBe(true);
+      expect(surchargeApplies("MONTHLY")).toBe(true);
+    });
+    it("allows it when the frequency is unknown", () => {
+      // Every migrated policy is null here — the original ETL dropped FORMA
+      // PAGO — and those rows DO carry recargo figures in the legacy data.
+      expect(surchargeApplies(null)).toBe(true);
+      expect(surchargeApplies(undefined)).toBe(true);
+    });
+  });
+
+  describe("resolveTaxRate", () => {
+    it("prefers the rate the policy was issued at", () => {
+      expect(resolveTaxRate(0.16, 0.08)).toBe(0.16);
+    });
+    it("falls back to the line of business", () => {
+      expect(resolveTaxRate(null, 0.08)).toBe(0.08);
+    });
+    it("falls back to the default when nothing is configured", () => {
+      expect(resolveTaxRate(null, null)).toBe(DEFAULT_TAX_RATE);
+      expect(resolveTaxRate(undefined, "")).toBe(DEFAULT_TAX_RATE);
+    });
+    it("accepts a zero rate as a real choice, not as absent", () => {
+      // An exempt line of business must read 0, not silently fall through to 8%.
+      expect(resolveTaxRate(null, 0)).toBe(0);
+    });
+    it("accepts Prisma's decimal strings", () => {
+      expect(resolveTaxRate(null, "0.0800")).toBe(0.08);
+    });
+  });
+});

apps/api/src/policies/premium.ts

@@ -0,0 +1,86 @@
+/**
+ * The premium arithmetic the Access capture form did in unbound calculated
+ * controls, moved somewhere it can be tested.
+ *
+ * Two figures are derived, everything else is keyed by hand:
+ *
+ *   base  = netPremium + surcharge + policyFee
+ *   tax   = round(base * rate)
+ *   total = base + tax
+ *
+ * The surcharge IS part of the taxable base. That is not an assumption — it is
+ * the only reading that reconciles the books. Policy 7006785 (MULT, semestral,
+ * two payments) prints IVA 52.03 and 47.84 against net premiums 610.86 / 589.71,
+ * surcharges 8.55 / 8.26 and policy fees 31.00 / 0.00; excluding the surcharge
+ * gives 51.35, which matches nothing on the page.
+ *
+ * The surcharge itself is NEVER derived. It is the carrier's financing charge
+ * for paying in installments, quoted per policy, so staff key it in. It only
+ * ever appears on a policy that is not paid annually or in a single exhibición
+ * — `surchargeApplies` is what the UI uses to grey the field out.
+ */
+
+/** Used when neither the policy nor its type carries a rate. Matches the
+ *  single row both legacy IMPUESTOS tables held (0.08 = 8%). */
+export const DEFAULT_TAX_RATE = 0.08;
+
+export type PaymentFrequencyValue =
+  | "ANNUAL"
+  | "SEMIANNUAL"
+  | "QUARTERLY"
+  | "MONTHLY"
+  | "SINGLE";
+
+/** Paying in more than one exhibición is what earns a surcharge. A null
+ *  frequency (every migrated row — Access's FORMA PAGO was dropped by the
+ *  original ETL) is treated as "unknown, allow it" rather than "annual":
+ *  refusing to show a figure that is sitting in the legacy data would hide it. */
+export function surchargeApplies(
+  frequency: PaymentFrequencyValue | null | undefined,
+): boolean {
+  return frequency !== "ANNUAL" && frequency !== "SINGLE";
+}
+
+function num(v: unknown): number {
+  if (v === null || v === undefined || v === "") return 0;
+  const n = typeof v === "number" ? v : Number(v);
+  return Number.isFinite(n) ? n : 0;
+}
+
+/** Half-up to cents, the way the printed policy rounds. */
+export function round2(n: number): number {
+  return Math.round((n + Number.EPSILON) * 100) / 100;
+}
+
+export interface PremiumParts {
+  netPremium?: unknown;
+  surcharge?: unknown;
+  policyFee?: unknown;
+}
+
+export function taxableBase(p: PremiumParts): number {
+  return round2(num(p.netPremium) + num(p.surcharge) + num(p.policyFee));
+}
+
+export function computeTax(p: PremiumParts, rate: number): number {
+  return round2(taxableBase(p) * rate);
+}
+
+export function computeTotal(p: PremiumParts, rate: number): number {
+  return round2(taxableBase(p) + computeTax(p, rate));
+}
+
+/** Rate ladder: the figure stored on the policy (so an old policy keeps the
+ *  rate it was issued at even after the catalog changes), else the rate on its
+ *  line of business, else the shipped default. */
+export function resolveTaxRate(
+  policyRate: unknown,
+  policyTypeRate: unknown,
+): number {
+  for (const candidate of [policyRate, policyTypeRate]) {
+    if (candidate === null || candidate === undefined || candidate === "") continue;
+    const n = Number(candidate);
+    if (Number.isFinite(n) && n >= 0) return n;
+  }
+  return DEFAULT_TAX_RATE;
+}

apps/web/src/app/catalogos/page.tsx

@@ -18,6 +18,10 @@ const TYPE: ChildConfig = {
   fields: [
     { key: "name", label: "Nombre" },
     { key: "shortDescription", label: "Descripción" },
+    // The rate is stored as a fraction, not a percentage, and the label has to
+    // say so: 8 typed here would tax a $600 premium $4,800. The API rejects
+    // anything above 1 rather than trusting the label alone.
+    { key: "taxRate", label: "IVA (0.08 = 8%)", type: "number", step: "0.0001" },
   ],
 };
 const ADJUSTER: ChildConfig = {

apps/web/src/app/globals.css

@@ -926,6 +926,15 @@ button {
   color: var(--ink-soft);
   margin-bottom: 0.4375rem;
 }
+/* Sub-label under an input: the computed figure behind an override field, or
+   why a field is disabled. Quiet enough not to compete with .field-label. */
+.field-hint {
+  display: block;
+  font-size: 0.75rem;
+  line-height: 1.35;
+  color: var(--muted-2);
+  margin-top: 0.3125rem;
+}
 .input {
   width: 100%;
   font-family: inherit;
@@ -940,6 +949,12 @@ button {
 .input::placeholder {
   color: var(--muted-2);
 }
+.input:disabled,
+.select:disabled {
+  background: var(--surface-2, var(--surface));
+  color: var(--muted-2);
+  cursor: not-allowed;
+}
 .input:focus {
   outline: none;
   border-color: var(--brand-600);

apps/web/src/app/polizas/[id]/page.tsx

@@ -26,7 +26,13 @@ import {
   premiumHeadline,
   SIN_NOMBRE,
 } from "@/lib/labels";
-import type { AdjusterRow, Installment, PolicyDetail } from "@/lib/types";
+import {
+  PAYMENT_FREQUENCY_LABELS,
+  type AdjusterRow,
+  type Installment,
+  type PolicyDetail,
+} from "@/lib/types";
+import { formatRate } from "@/lib/premium";
 
 export default function PolizaDetailPage({
   params,
@@ -186,6 +192,10 @@ function ChildrenEditor({
   const INSTALLMENTS: ChildConfig = {
     apiKind: "installments",
     title: "Pagos",
+    // A policy paid in several exhibiciones prices each payment on its own, so
+    // the whole premium breakdown repeats per row — that is the two-row money
+    // block on the Access form. `amount` stays what was actually collected and
+    // is deliberately separate from `total`; they differ by rounding.
     fields: [
       { key: "sequence", label: "Sec.", type: "number" },
       { key: "amount", label: "Monto", type: "number" },
@@ -195,6 +205,12 @@ function ChildrenEditor({
       { key: "paidDate", label: "Pagado", type: "date" },
       { key: "checkNumber", label: "Cheque" },
       { key: "isCash", label: "Efectivo", type: "checkbox" },
+      { key: "netPremium", label: "Prima neta", type: "number" },
+      { key: "surcharge", label: "Recargo", type: "number" },
+      { key: "policyFee", label: "Derecho", type: "number" },
+      { key: "tax", label: "IVA", type: "number" },
+      { key: "total", label: "Prima total", type: "number" },
+      { key: "commission", label: "Comisión", type: "number" },
     ],
   };
   const VEHICLES: ChildConfig = {
@@ -412,15 +428,40 @@ function CondicionesSection({ data }: { data: PolicyDetail }) {
               data.coveragePeriodDays ? `${data.coveragePeriodDays} días` : null
             }
           />
+          <KV
+            label="Forma de pago"
+            value={
+              data.paymentFrequency
+                ? PAYMENT_FREQUENCY_LABELS[data.paymentFrequency]
+                : null
+            }
+          />
           <KV label="Prima neta" value={formatMoney(data.netPremium, cur)} />
+          {/* Only ever set on a policy paid in installments, so showing an
+              empty row on the other 98% would be noise. */}
+          {data.surcharge != null && Number(data.surcharge) !== 0 && (
+            <KV label="Recargo" value={formatMoney(data.surcharge, cur)} />
+          )}
           <KV label="Derecho de póliza" value={formatMoney(data.policyFee, cur)} />
-          <KV label="Comisión" value={formatMoney(data.commission, cur)} />
-          <KV label="Honorarios" value={formatMoney(data.brokerFee, cur)} />
+          {/* Access never stored IVA — it was a calculated control on the form
+              — so every migrated policy reads null here until it is edited. */}
+          {data.tax != null && (
+            <KV
+              label={
+                data.taxRate != null
+                  ? `IVA (${formatRate(Number(data.taxRate))})`
+                  : "IVA"
+              }
+              value={formatMoney(data.tax, cur)}
+            />
+          )}
           {/* The legacy `total` is 0 or null on all but 2 of 2378 policies —
               only show it when it actually carries a figure. */}
           {data.total != null && Number(data.total) > 0 && (
-            <KV label="Total" value={formatMoney(data.total, cur)} />
+            <KV label="Prima total" value={formatMoney(data.total, cur)} />
           )}
+          <KV label="Comisión" value={formatMoney(data.commission, cur)} />
+          <KV label="Honorarios" value={formatMoney(data.brokerFee, cur)} />
           <KV
             label="Liquidación"
             value={

apps/web/src/components/ChildCollection.tsx

@@ -9,6 +9,9 @@ export type FieldDef = {
   type?: "text" | "number" | "date" | "checkbox" | "select";
   options?: { value: string; label: string }[];
   width?: number;
+  /** Numeric granularity. Defaults to money (0.01); a tax rate stored as a
+   *  fraction needs finer, or the browser rejects 0.0825 as off-step. */
+  step?: string;
 };
 
 export type ChildConfig = {
@@ -158,7 +161,7 @@ export function ChildCollection({
                 <input
                   className="input"
                   type={f.type === "number" ? "number" : f.type === "date" ? "date" : "text"}
-                  step={f.type === "number" ? "0.01" : undefined}
+                  step={f.type === "number" ? f.step ?? "0.01" : undefined}
                   value={String(values[f.key] ?? "")}
                   onChange={(e) => setValues({ ...values, [f.key]: e.target.value })}
                 />

apps/web/src/components/PolicyForm.tsx

@@ -4,12 +4,22 @@ import { useEffect, useState } from "react";
 import { useRouter } from "next/navigation";
 import { CustomerPicker } from "@/components/CustomerPicker";
 import { createPolicy, getLookups, updatePolicy } from "@/lib/api";
-import type {
-  Currency,
-  LookupsResponse,
-  PolicyDetail,
-  PolicyInput,
+import {
+  PAYMENT_FREQUENCY_LABELS,
+  type Currency,
+  type LookupsResponse,
+  type PaymentFrequency,
+  type PolicyDetail,
+  type PolicyInput,
 } from "@/lib/types";
+import {
+  computeTax,
+  computeTotal,
+  formatRate,
+  resolveTaxRate,
+  surchargeApplies,
+  taxableBase,
+} from "@/lib/premium";
 
 function toDateInput(v: string | null | undefined): string {
   if (!v) return "";
@@ -36,9 +46,16 @@ type V = {
   policyFrom: string;
   policyTo: string;
   netPremium: string;
+  surcharge: string;
   policyFee: string;
   brokerFee: string;
   commission: string;
+  /** Blank means "use the computed figure". Only ever holds a value once the
+   *  operator overrides it, so a later change to prima neta keeps flowing
+   *  through instead of being frozen by a value the form itself wrote. */
+  tax: string;
+  total: string;
+  paymentFrequency: PaymentFrequency | "";
   currency: Currency;
   liquidated: boolean;
   liquidationNumber: string;
@@ -58,9 +75,13 @@ function initial(p?: PolicyDetail): V {
     policyFrom: toDateInput(p?.policyFrom),
     policyTo: toDateInput(p?.policyTo),
     netPremium: p?.netPremium != null ? String(p.netPremium) : "",
+    surcharge: p?.surcharge != null ? String(p.surcharge) : "",
     policyFee: p?.policyFee != null ? String(p.policyFee) : "",
     brokerFee: p?.brokerFee != null ? String(p.brokerFee) : "",
     commission: p?.commission != null ? String(p.commission) : "",
+    tax: p?.tax != null ? String(p.tax) : "",
+    total: p?.total != null ? String(p.total) : "",
+    paymentFrequency: p?.paymentFrequency ?? "",
     currency: (p?.currency as Currency) ?? "MXN",
     liquidated: p?.liquidated ?? false,
     liquidationNumber: p?.liquidationNumber ?? "",
@@ -101,6 +122,27 @@ export function PolicyForm({
     setV((p) => ({ ...p, [k]: val }));
   }
 
+  // IVA and Total are the only two figures the form derives. Everything else,
+  // the recargo included, is keyed by hand — the carrier quotes the financing
+  // charge, we do not compute it.
+  const selectedType = lookups?.types.find((t) => t.id === v.policyTypeId);
+  const taxRate = resolveTaxRate(policy?.taxRate, selectedType?.taxRate);
+  const parts = {
+    netPremium: v.netPremium,
+    // A recargo on an annual policy is a data-entry mistake, so it is dropped
+    // from the arithmetic as well as disabled in the UI. Otherwise switching
+    // ANNUAL after typing one would leave it silently inflating the IVA.
+    surcharge: surchargeApplies(v.paymentFrequency || null) ? v.surcharge : "",
+    policyFee: v.policyFee,
+  };
+  const computedTax = computeTax(parts, taxRate);
+  const computedTotal = computeTotal(parts, taxRate);
+  // Blank field = take the computed figure. A typed one wins, so staff can key
+  // the carrier's rounding verbatim when it disagrees with ours by a centavo.
+  const effectiveTax = v.tax.trim() === "" ? computedTax : Number(v.tax);
+  const effectiveTotal = v.total.trim() === "" ? computedTotal : Number(v.total);
+  const showSurcharge = surchargeApplies(v.paymentFrequency || null);
+
   async function submit(e: React.FormEvent) {
     e.preventDefault();
     if (!customerId) {
@@ -118,9 +160,17 @@ export function PolicyForm({
       policyFrom: s(v.policyFrom),
       policyTo: s(v.policyTo),
       netPremium: numOrUndef(v.netPremium),
+      surcharge: showSurcharge ? numOrUndef(v.surcharge) : undefined,
       policyFee: numOrUndef(v.policyFee),
       brokerFee: numOrUndef(v.brokerFee),
       commission: numOrUndef(v.commission),
+      // The derived figures are persisted, not recomputed on read: the printed
+      // policy is the record of truth and a later rate change must not silently
+      // restate what was issued. `taxRate` rides along for the same reason.
+      tax: Number.isFinite(effectiveTax) ? effectiveTax : undefined,
+      taxRate,
+      total: Number.isFinite(effectiveTotal) ? effectiveTotal : undefined,
+      paymentFrequency: v.paymentFrequency || undefined,
       currency: v.currency,
       liquidated: v.liquidated,
       liquidationNumber: s(v.liquidationNumber),
@@ -208,7 +258,7 @@ export function PolicyForm({
       </div>
 
       <div className="card" style={{ padding: 20, marginBottom: 16 }}>
-        <h2 className="section-title" style={{ marginBottom: 14 }}>Vigencia y prima</h2>
+        <h2 className="section-title" style={{ marginBottom: 14 }}>Vigencia</h2>
         <div className="form-grid">
           <label className="field">
             <span className="field-label">Emisión</span>
@@ -225,21 +275,84 @@ export function PolicyForm({
             <input className="input" type="date" value={v.policyTo}
               onChange={(e) => set("policyTo", e.target.value)} />
           </label>
+          <label className="field">
+            <span className="field-label">Forma de pago</span>
+            <select className="select" value={v.paymentFrequency}
+              onChange={(e) =>
+                set("paymentFrequency", e.target.value as PaymentFrequency | "")
+              }>
+              <option value="">—</option>
+              {(
+                Object.keys(PAYMENT_FREQUENCY_LABELS) as PaymentFrequency[]
+              ).map((f) => (
+                <option key={f} value={f}>{PAYMENT_FREQUENCY_LABELS[f]}</option>
+              ))}
+            </select>
+          </label>
+        </div>
+      </div>
+
+      <div className="card" style={{ padding: 20, marginBottom: 16 }}>
+        <h2 className="section-title" style={{ marginBottom: 4 }}>Primas</h2>
+        <p className="muted" style={{ fontSize: 12, marginBottom: 14 }}>
+          IVA y prima total se calculan solos sobre (prima neta + recargo +
+          derecho de póliza). Puede sobrescribirlos si la póliza impresa
+          redondea distinto.
+        </p>
+        <div className="form-grid">
           <label className="field">
             <span className="field-label">Prima neta</span>
             <input className="input" type="number" step="0.01" value={v.netPremium}
               onChange={(e) => set("netPremium", e.target.value)} />
           </label>
+          <label className="field">
+            <span className="field-label">Recargo</span>
+            <input className="input" type="number" step="0.01" value={v.surcharge}
+              disabled={!showSurcharge}
+              onChange={(e) => set("surcharge", e.target.value)} />
+            <span className="field-hint">
+              {showSurcharge
+                ? "Lo cotiza la aseguradora — se captura a mano."
+                : "No aplica en pago anual ni de contado."}
+            </span>
+          </label>
           <label className="field">
             <span className="field-label">Derecho de póliza</span>
             <input className="input" type="number" step="0.01" value={v.policyFee}
               onChange={(e) => set("policyFee", e.target.value)} />
           </label>
+          <label className="field">
+            <span className="field-label">IVA ({formatRate(taxRate)})</span>
+            <input className="input" type="number" step="0.01"
+              placeholder={computedTax.toFixed(2)} value={v.tax}
+              onChange={(e) => set("tax", e.target.value)} />
+            <span className="field-hint">
+              Calculado: {computedTax.toFixed(2)} sobre base{" "}
+              {taxableBase(parts).toFixed(2)}
+              {selectedType?.taxRate == null &&
+                policy?.taxRate == null &&
+                " · tasa por omisión, configúrela en Catálogos"}
+            </span>
+          </label>
+          <label className="field">
+            <span className="field-label">Prima total</span>
+            <input className="input" type="number" step="0.01"
+              placeholder={computedTotal.toFixed(2)} value={v.total}
+              onChange={(e) => set("total", e.target.value)} />
+            <span className="field-hint">
+              Calculado: {computedTotal.toFixed(2)}
+            </span>
+          </label>
           <label className="field">
             <span className="field-label">Comisión</span>
             <input className="input" type="number" step="0.01" value={v.commission}
               onChange={(e) => set("commission", e.target.value)} />
           </label>
+          <label className="field">
+            <span className="field-label">Honorarios</span>
+            <input className="input" type="number" step="0.01" value={v.brokerFee}
+              onChange={(e) => set("brokerFee", e.target.value)} />
+          </label>
         </div>
       </div>
 

apps/web/src/lib/premium.ts

@@ -0,0 +1,79 @@
+import type { PaymentFrequency } from "./types";
+
+/**
+ * Client-side twin of apps/api/src/policies/premium.ts. Duplicated rather than
+ * shared because the API and the web app do not share a package today, and
+ * both need it: the form computes IVA and Total live as the operator types,
+ * the API stores what it is sent.
+ *
+ *   base  = prima neta + recargo + derecho de póliza
+ *   IVA   = round(base * tasa)
+ *   Total = base + IVA
+ *
+ * The recargo is inside the taxable base — that is what reconciles the Access
+ * books (policy 7006785 prints IVA 52.03 on 610.86 + 8.55 + 31.00; leaving the
+ * recargo out gives 51.35, which matches nothing on the page).
+ */
+
+/** Applied when neither the policy nor its type carries a rate. The single
+ *  row both legacy IMPUESTOS tables held. */
+export const DEFAULT_TAX_RATE = 0.08;
+
+/** Paying in more than one exhibición is what earns a recargo. A null
+ *  frequency (every migrated policy) is treated as "unknown, allow it": the
+ *  legacy recargo figures are real and hiding the field would hide them. */
+export function surchargeApplies(
+  frequency: PaymentFrequency | null | undefined,
+): boolean {
+  return frequency !== "ANNUAL" && frequency !== "SINGLE";
+}
+
+export function num(v: string | number | null | undefined): number {
+  if (v === null || v === undefined || v === "") return 0;
+  const n = typeof v === "number" ? v : Number(String(v).trim());
+  return Number.isFinite(n) ? n : 0;
+}
+
+/** Half-up to cents, matching how the printed policy rounds. */
+export function round2(n: number): number {
+  return Math.round((n + Number.EPSILON) * 100) / 100;
+}
+
+export interface PremiumParts {
+  netPremium: string | number | null | undefined;
+  surcharge: string | number | null | undefined;
+  policyFee: string | number | null | undefined;
+}
+
+export function taxableBase(p: PremiumParts): number {
+  return round2(num(p.netPremium) + num(p.surcharge) + num(p.policyFee));
+}
+
+export function computeTax(p: PremiumParts, rate: number): number {
+  return round2(taxableBase(p) * rate);
+}
+
+export function computeTotal(p: PremiumParts, rate: number): number {
+  return round2(taxableBase(p) + computeTax(p, rate));
+}
+
+/** Rate ladder: what the policy was issued at, else its line of business, else
+ *  the default. Keeps an old policy reading back at its original rate after
+ *  somebody edits the catalog. */
+export function resolveTaxRate(
+  policyRate: string | number | null | undefined,
+  policyTypeRate: string | number | null | undefined,
+): number {
+  for (const candidate of [policyRate, policyTypeRate]) {
+    if (candidate === null || candidate === undefined || candidate === "") continue;
+    const n = Number(candidate);
+    if (Number.isFinite(n) && n >= 0) return n;
+  }
+  return DEFAULT_TAX_RATE;
+}
+
+/** 0.08 -> "8%". Rates are stored as fractions but read as percentages. */
+export function formatRate(rate: number): string {
+  const pct = round2(rate * 100);
+  return `${pct}%`;
+}

apps/web/src/lib/types.ts

@@ -3,6 +3,24 @@
 
 export type Currency = "USD" | "MXN";
 
+/** How the premium is split into payments. Anything other than ANNUAL/SINGLE
+ *  is what earns a recargo. Null on every migrated policy — the original ETL
+ *  dropped Access's FORMA PAGO column entirely. */
+export type PaymentFrequency =
+  | "ANNUAL"
+  | "SEMIANNUAL"
+  | "QUARTERLY"
+  | "MONTHLY"
+  | "SINGLE";
+
+export const PAYMENT_FREQUENCY_LABELS: Record<PaymentFrequency, string> = {
+  ANNUAL: "Anual",
+  SEMIANNUAL: "Semestral",
+  QUARTERLY: "Trimestral",
+  MONTHLY: "Mensual",
+  SINGLE: "Contado",
+};
+
 export type Role = "ADMIN" | "MANAGER" | "STAFF" | "VIEWER";
 
 export type Ability =
@@ -289,6 +307,16 @@ export interface Installment {
   paidDate: string | null;
   checkNumber: string | null;
   isCash: boolean;
+  /** Per-payment premium breakdown — a policy paid in several exhibiciones
+   *  prices each one separately. `amount` is what was actually collected and
+   *  can differ from `total` by rounding; it is not derived from these. */
+  netPremium: string | null;
+  surcharge: string | null;
+  policyFee: string | null;
+  tax: string | null;
+  taxRate: string | null;
+  total: string | null;
+  commission: string | null;
 }
 
 export interface Vehicle {
@@ -398,10 +426,14 @@ export interface PolicyInput {
   policyTo?: string;
   coveragePeriodDays?: number;
   netPremium?: number;
+  surcharge?: number;
   policyFee?: number;
   brokerFee?: number;
   commission?: number;
+  tax?: number;
+  taxRate?: number;
   total?: number;
+  paymentFrequency?: PaymentFrequency;
   currency?: Currency;
   observations?: string;
   notes?: string;
@@ -419,6 +451,13 @@ export interface InstallmentInput {
   paidDate?: string;
   checkNumber?: string;
   isCash?: boolean;
+  netPremium?: number;
+  surcharge?: number;
+  policyFee?: number;
+  tax?: number;
+  taxRate?: number;
+  total?: number;
+  commission?: number;
 }
 export interface VehicleInput {
   make?: string;
@@ -469,6 +508,10 @@ export interface PolicyTypeRow {
   id: string;
   name: string;
   shortDescription: string | null;
+  /** IVA fraction for this line of business, 0.08 = 8%. Null means "not
+   *  configured" and the form falls back to DEFAULT_TAX_RATE — it does NOT
+   *  mean the line is untaxed. Serialized as a decimal string by Prisma. */
+  taxRate: string | null;
   _count?: { policies: number };
 }
 export interface AdjusterRow {
@@ -567,10 +610,14 @@ export interface PolicyDetail {
   policyTo: string | null;
   coveragePeriodDays: number | null;
   netPremium: string | null;
+  surcharge: string | null;
   policyFee: string | null;
   brokerFee: string | null;
   commission: string | null;
+  tax: string | null;
+  taxRate: string | null;
   total: string | null;
+  paymentFrequency: PaymentFrequency | null;
   currency: string | null;
   observations: string | null;
   notes: string | null;