How to sign a PDF with your UANATACA certificate

Sign PDFs with your UANATACA (.p12) certificate from the browser, free and with nothing to install. firmar.ec completes the chain even if your .p12 ships leaf-only.

By IDK Manager Team ·

UANATACA is an ARCOTEL-accredited certification authority that issues electronic-signature certificates in Ecuador (often delivered through resellers such as Signare/ArgosData). This guide shows how to sign a PDF with your UANATACA .p12 certificate free, in your browser, with nothing to install — including from your phone.

Total time: 2-3 minutes per PDF.

The UANATACA quirk: the “leaf-only” .p12

UANATACA certificates are usually delivered in a .p12 that contains only the holder’s certificate (the “leaf”), without the intermediate CA (UANATACA CA2 2016). Many browser-only verifiers fail on these files because they cannot build the leaf → CA2 2016 → root chain.

firmar.ec handles it automatically: it bundles UANATACA’s intermediate CA, so it completes the chain and recognises your certificate with no extra steps. (To check before signing, use Validate certificate.)

What you need

  • Your UANATACA certificate as a .p12 / .pfx file and its password.
  • The PDF you want to sign.
  • A modern browser (Chrome, Firefox, Safari, Edge).

How to sign

The flow is the same as how to sign a PDF on firmar.ec: load the PDF, place the signature box, upload your UANATACA .p12, enter the password and download the signed PDF. Everything happens in your browser — your private key never leaves your device.

  1. Open app.firmar.ec/firmar.
  2. Load the PDF and place the visible seal (includes your name, “UANATACA” as issuer and a verification QR).
  3. Upload your UANATACA .p12 and enter the password.
  4. Review the summary and press Sign PDF.
  5. Download the <document>-firmado.pdf (or share it via WhatsApp/email).

After signing

Validate your own signature at app.firmar.ec/verificar: it confirms integrity, that the UANATACA certificate chains to its ARCOTEL-accredited root, and the revocation status. The result is PAdES Baseline B-B (ETSI EN 319 142-1), valid in Adobe Reader, the MINTEL validator and any standard PAdES verifier.

FAQ

My UANATACA .p12 showed “issuer not recognised” elsewhere. Why? Because it shipped leaf-only and those verifiers did not complete the chain. firmar.ec bundles UANATACA’s intermediate.

Is it free? Yes. firmar.ec is free for personal use and open source (AGPL-3.0).

Does it work on mobile? Yes, on any modern mobile browser.