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v1.5Official documentation for the LX CloudPos API · stable in production
v1.5 (current)Business rulesTax exemptions

Tax exemptions

Some customers (governments, NGOs, free trade zones) hold a tax exemption resolution for VAT issued by the Ministry of Finance (Hacienda).

Exemption (exoneración) ≠ exempt (exención). The exemption resolution (exoneración) applies to a customer with a valid resolution; the exempt status (exención) applies to the product. This section covers exemption resolutions only.

The real mechanism: idExoneracion, never an amount

To exempt a line you send idExoneracion (the id of an exemption already registered for that customer), and nothing else. The exempted amount is never sent: the server calculates it from the product’s real VAT rate and the percentage authorized on the exemption, capping the result so a line never exempts more tax than it actually carries.

montoExoneracion exists in the contract but is IGNORED. It’s a field left over from an earlier version of the API: it’s still accepted in the JSON so integrators who already send it don’t get a validation error, but its value is never used for anything — it isn’t added, subtracted, or reflected on the document. If montoExoneracion is sent without idExoneracion, the line comes out fully taxed, with no error and no warning. See FacturaApiLineaDto for the field’s full detail.

{
  "idProducto": 101,
  "cantidad": 1,
  "idExoneracion": 7
}

Where idExoneracion comes from

The integrator gets it from GET /api/v1/clientes/{identificacion}, in the response’s exoneraciones array (ClienteApiResponseDto). Each item carries its idExoneracion, the authorized percentage, issue/expiration dates, and a vigente boolean already resolved by the server:

{
  "idCliente": 46,
  "identificacion": "117890123",
  "...": "...",
  "exoneraciones": [
    {
      "idExoneracion": 7,
      "tipoDocumento": "03",
      "tipoDocumentoNombre": "Exoneración compras autorizadas de Zona Franca",
      "numeroDocumento": "EX-2026-00412",
      "nombreInstitucion": "PROCOMER",
      "fechaEmision": "2026-01-10T00:00:00Z",
      "fechaExpiracion": "2027-01-10T00:00:00Z",
      "porcentajeExoneracion": 100,
      "estado": true,
      "vigente": true
    }
  ]
}

Exemptions themselves (creation, editing, validity) are not managed through the API — they’re registered from the POS. GET /clientes/{identificacion} only exposes them so the integrator knows which id to send.

Validation when issuing

The id is validated against the document’s customer and the exemption’s validity; one that doesn’t pass doesn’t silently issue with full VAT — it returns 400:

CauseWhen it happens
idExoneracion was sent without a cliente on the documentThe exemption belongs to a registered customer; it doesn’t apply to a Tiquete Electrónico with no recipient.
The id doesn’t exist or doesn’t belong to the document’s customerThe idExoneracion belongs to another customer, or doesn’t exist in the tenant.
The exemption is inactive (estado: false)It was deactivated in the POS.
The exemption is expired (fechaExpiracion in the past)Same condition as vigente: false in the GET /clientes/{identificacion} response.

Rejection example:

{ "error": "Línea 1: la exoneración 7 venció el 10/01/2026." }

Calculation behavior

The percentage authorized on the exemption is applied to the line’s real VAT, capped at the product’s rate: a 100% exemption on a product taxed at 2% exempts 2 points, not 13. With a partial exemption (for example 50%):

  • 50% of the VAT is charged normally.
  • 50% of the VAT is exempted (not charged).

LX CloudPos automatically splits the amount between “taxed base” and “exempted base”. See totals calculation.

See also: VAT.

DiscountsOther charges