El Salvador DUI Verification API: Validate the Documento Único de Identidad

Updated November 2026

This guide shows how to verify a DUI in El Salvador with Verifik’s API: the endpoint, its parameters, a request you can paste into a terminal, the documented response and errors, and what to watch for when you put it in production. Everything below comes from the official endpoint documentation.

About the DUI in El Salvador

The Documento Único de Identidad (DUI) is El Salvador’s national ID, issued by the Registro Nacional de las Personas Naturales (RNPN) to citizens aged 18 and over. The number has nine digits, usually printed as eight digits, a hyphen and a check digit.

The DUI is also used as the taxpayer number for individuals, so it appears in banking, payroll and remittance flows. Verifik’s endpoint takes the DUI and the date of birth and returns the holder’s full name.

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How to call the El Salvador DUI API

Endpoint: GET https://api.verifik.co/v2/sv/dui. Send your token in the Authorization: Bearer header. Parameters, as documented:

Request example with placeholder values (replace them with your user’s data):

curl --location --request GET 'https://api.verifik.co/v2/sv/dui?documentNumber=012345678&dateOfBirth=15/03/1990' \
--header 'Accept: application/json' \
--header 'Authorization: Bearer <token>'

200 response from the docs (personal data masked):

{
  "data": {
    "documentNumber": "12*****89",
    "fullName": "J*** P****"
  },
  "signature": {
    "message": "Certified by Verifik.co",
    "dateTime": "January 16, 2024 3:44 PM"
  },
  "id": "SV001"
}

A successful call returns HTTP 200 with a data object containing: documentNumber, fullName. Every response also carries a signature (timestamp and “Certified by Verifik.co”) and a unique id you can store as evidence of the check.

Documented errors for /v2/sv/dui

• 401 UNAUTHORIZED (“Authentication required”): the token is missing or invalid; check the Authorization header.
• 409 MissingParameter (“missing dateOfBirth”): a required parameter is missing or has an invalid value; fix the request instead of retrying it as is.
• 500 InternalServerError (“Server error”): a server or source error; retry with backoff and log the request id.

Integration tips

• Remove spaces from the DUI before sending it; the docs ask for the number without spaces.
• The date of birth is mandatory and must be DD/MM/YYYY (409 missing dateOfBirth otherwise).
• The response only returns fullName, so plan a name comparison step on your side.
• For remittance and wallet onboarding, combine the DUI check with a selfie liveness check to stop borrowed documents.

Personal data and terms of use

Identity lookups process personal data. Use the API only for a lawful purpose you can document, such as onboarding, fraud prevention or contract checks, collect consent where the local law requires it, and keep only the fields you need. Usage is governed by the smartCHECK terms and conditions.

Pricing

Each successful request consumes credits from your Verifik plan. Current plans and per-endpoint costs are on the smartCHECK pricing page.

Related guides and documentation

• Guatemala CUI verification API
• Honduras DNI verification API
• Endpoint documentation (English)
• Documentation in Spanish

Start testing

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