Comparison
When to use Fdo., and when not to.
The three tools listed here cover different things. Fdo. is the right option when you need simple signature in batches over standard PDFs. For qualified signature or collaborative flows with audit, there are better options. This page explains it without marketing.
Quick summary
| Fdo. | National e-sign | DocuSign / Signaturit | |
|---|---|---|---|
| Signature type | Simple (image on PDF) | Qualified (digital certificate) | Advanced (OTP, audit trail) |
| Typical use case | Signing batches of identical PDFs | Filing with public administrations | Contracts with a remote third party |
| Batch processing | Yes, hundreds at a time | Limited (folder-based bulk signing) | Yes, with templates |
| Data on a server | No, browser only | No, desktop | Yes (SaaS) |
| Cost | Free | Free | Subscription (with limited free plan) |
| Requires sign-up | No | Issued certificate required | Account required |
| Valid for public administrations | No | Yes | Limited (depends on the procedure) |
| Multi-signer approval flow | No | No | Yes |
| Runs in the browser | Yes | Desktop app | Yes |
When to pick each one
Pick Fdo. if…
- You sign many similar PDFs at one time (month-end, quarter-end, batch of certificates).
- Simple signature is enough: private contracts, client copies, internal certificates, quotes.
- You're uncomfortable sending documentation to a third-party server, especially if it contains personal data.
- You don't want to create another account or add another data processor to your privacy chain.
Pick the national e-sign tool if…
- You're filing the document with a public administration (tax authority, social security, courts).
- You have a digital certificate (FNMT, DNIe, ACA or any qualified one under eIDAS).
- The recipient explicitly requires qualified signature, not simple.
Pick DocuSign, Signaturit or similar if…
- You need a remote third party to sign the document (a client, a supplier) with prior identification by SMS, email or video.
- The flow needs tracking: sent, viewed, signed, rejected, with timestamp.
- Your sector requires advanced signature with audit trail (banking, insurance, healthcare).
Combining them makes sense
These three tools are not mutually exclusive. An accounting practice can use the national e-sign tool for tax-authority filings, DocuSign for new-client contracts where identification is needed, and Fdo. for signing 80 client certificates in January in one go.