diff --git a/src/api/SIGCM2.Api/Contracts/Fiscal/FiscalContracts.cs b/src/api/SIGCM2.Api/Contracts/Fiscal/FiscalContracts.cs
new file mode 100644
index 0000000..caf8618
--- /dev/null
+++ b/src/api/SIGCM2.Api/Contracts/Fiscal/FiscalContracts.cs
@@ -0,0 +1,123 @@
+using SIGCM2.Application.IngresosBrutos.Dtos;
+using SIGCM2.Application.TiposDeIva.Dtos;
+using SIGCM2.Domain.Fiscal;
+
+namespace SIGCM2.Api.Contracts.Fiscal;
+
+// ── IVA Request records ───────────────────────────────────────────────────────
+
+/// <summary>ADM-009: Create TipoDeIva request body.</summary>
+public sealed record CreateTipoDeIvaRequest(
+    string? Codigo,
+    string? Descripcion,
+    decimal? Porcentaje,
+    bool? AplicaIVA,
+    string? VigenciaDesde,
+    string? VigenciaHasta = null);
+
+/// <summary>
+/// ADM-009: Update TipoDeIva request body — only cosmetic fields.
+/// Porcentaje is intentionally absent; any attempt to pass it in the body
+/// is detected via raw JSON inspection and returns 409.
+/// </summary>
+public sealed record UpdateTipoDeIvaRequest(
+    string? Codigo,
+    string? Descripcion,
+    bool? AplicaIVA,
+    bool? Activo);
+
+/// <summary>ADM-009: Create new TipoDeIva version request body.</summary>
+public sealed record NuevaVersionTipoDeIvaRequest(
+    decimal? Porcentaje,
+    string? VigenciaDesde);
+
+// ── IIBB Request records ──────────────────────────────────────────────────────
+
+/// <summary>ADM-009: Create IngresosBrutos request body.</summary>
+public sealed record CreateIngresosBrutosRequest(
+    string? Provincia,
+    string? Descripcion,
+    decimal? Alicuota,
+    string? VigenciaDesde,
+    string? VigenciaHasta = null);
+
+/// <summary>
+/// ADM-009: Update IngresosBrutos request body — only cosmetic fields.
+/// Alicuota and Provincia are intentionally absent.
+/// </summary>
+public sealed record UpdateIngresosBrutosRequest(
+    string? Descripcion,
+    bool? Activo);
+
+/// <summary>ADM-009: Create new IngresosBrutos version request body.</summary>
+public sealed record NuevaVersionIngresosBrutosRequest(
+    decimal? Alicuota,
+    string? VigenciaDesde);
+
+// ── Shared Response records ───────────────────────────────────────────────────
+
+/// <summary>ADM-009: Response for nueva-version operations.</summary>
+public sealed record NuevaVersionResponse(
+    int PredecesoraId,
+    int NuevaVersionId);
+
+// ── Mapper ────────────────────────────────────────────────────────────────────
+
+/// <summary>
+/// Maps Application-layer DTOs to API response shapes.
+/// Application DTOs are already well-formed for most cases;
+/// IIBB Provincia is mapped to its display string for the API.
+/// </summary>
+public static class FiscalContractMapper
+{
+    public static object ToIvaResponse(TipoDeIvaDto dto) => new
+    {
+        dto.Id,
+        dto.Codigo,
+        dto.Descripcion,
+        dto.Porcentaje,
+        dto.AplicaIVA,
+        dto.Activo,
+        dto.VigenciaDesde,
+        dto.VigenciaHasta,
+        dto.PredecesorId,
+        dto.FechaCreacion,
+        dto.FechaModificacion
+    };
+
+    public static object ToIibbResponse(IngresosBrutosDto dto) => new
+    {
+        dto.Id,
+        Provincia = dto.Provincia.ToDisplayString(),
+        dto.Descripcion,
+        dto.Alicuota,
+        dto.Activo,
+        dto.VigenciaDesde,
+        dto.VigenciaHasta,
+        dto.PredecesorId,
+        dto.FechaCreacion,
+        dto.FechaModificacion
+    };
+
+    public static object ToHistorialIvaResponse(HistorialCadenaDto dto) => new
+    {
+        dto.Id,
+        dto.Codigo,
+        dto.Porcentaje,
+        dto.VigenciaDesde,
+        dto.VigenciaHasta,
+        dto.PredecesorId,
+        dto.Version
+    };
+
+    public static object ToHistorialIibbResponse(HistorialCadenaIibbDto dto) => new
+    {
+        dto.Id,
+        Provincia = dto.Provincia.ToDisplayString(),
+        dto.Alicuota,
+        dto.VigenciaDesde,
+        dto.VigenciaHasta,
+        dto.PredecesorId,
+        dto.Version
+    };
+}