Keeping without losing.
Archiving, retention periods and disposal of signed documents.
Signing is the most visible moment in a document's life, but it is only the beginning. Afterward comes a period that may last years or decades, during which the document must remain findable, readable and provable. And at the end, when it is no longer needed, it must be disposed of with the same rigor with which it was kept. All three, preserving, proving and destroying, are part of the same process.
The four properties of a good archive
The discipline of records management, set out in standards such as ISO 15489, requires a preserved document to maintain four properties over time.
- Authenticity. It is what it claims to be, produced by whoever claims to have produced it.
- Integrity. It is complete and unaltered.
- Reliability. Its content faithfully reflects the act it documents.
- Usability. It can be located, retrieved and read whenever it is needed.
In a digitally signed document, the first three depend largely on the signature and its evidence. The fourth depends on the archive, and it is the one most often neglected.
Reading it twenty years from now
A document that cannot be opened is a lost document, even if it still exists. That is why formats matter. The PDF/A family, defined in the ISO 19005 standard, establishes a subset of PDF designed for preservation: it embeds fonts, prohibits content that depends on external resources, and avoids features that may stop working. Combined with long term signatures, it allows the document to remain readable and verifiable long after the system that created it has disappeared.
How long to keep it
There is no universal period. It is set by the law of each country and each subject area: accounting, employment, health and notarial records have different periods, sometimes counted from the date of signing and sometimes from the end of the relationship. The recommended practice is to maintain a retention schedule: for each type of document, the period, the rule that requires it, and the person responsible for applying it.
| Document type | When the period starts | What to keep besides the document |
|---|---|---|
| Contract | From its termination, plus the period for claims. | Signature evidence and approved versions. |
| Employment document | From the end of the employment relationship. | Proof of delivery and acceptance. |
| Informed consent | According to the applicable health regulations. | The exact version shown to the patient. |
Specific periods vary by country and subject area; the table shows criteria, not legal periods.
Destruction is also an obligation
Personal data protection laws establish that data should not be kept longer than necessary for its purpose. An archive that keeps everything forever is not prudent: it accumulates risk. When the retention period expires, and no litigation or investigation requires the document to be kept, it should be deleted along with its copies, and that deletion should be recorded.
- A retention schedule for each document type, with its legal basis.
- Standard preservation formats and long term signatures.
- Copies in more than one location, with periodic integrity checks.
- A documented way to suspend destruction in the event of litigation.
- Recorded deletion when the period expires, copies included.
- An agreed exit with every provider: full export and verifiable deletion.
Preserving a signed document means maintaining its authenticity, integrity, reliability and usability for the entire period the law requires. That calls for formats designed to last, a retention schedule, and the discipline to destroy, with a record, whatever no longer needs to be kept.