Trusted Document Timestamping
Available only in the paid plans
Timestamping a document proves that the contents of the document existed in that form on that particular date and time so that no one can backdate the timestamp entries. It also marks the signature with date and time as proof of integrity.
Timestamping also proves that the digital certificate used in the signing process is valid at the time of signing. This also helps in creating long term validity (LTV) on the signed document where all required information is needed to validate the authenticity of digital signature even after that expiry of digital certificates.
The timestamps added to the documents via trusted document timestamping are obtained from a trusted third-party service provider called a timestamping authority (TSA), which follow all required standards for cryptographic timestamping such as RFC 3161 & RFC 5816.
Trusted timestamping gives strong legal evidence about the timing of action performed which no one can dispute. It also preserves the document signatures and verifies the integrity of its contents from when it was signed even a long-time into the future, even when the original validation data might be no longer available or the digital signature certificates themselves have expired. Thus, this helps prove that the signed document existed in the given form at the time of signing and is the original unchanged copy. This method of preservation is called Long Term Archival (LTA), which is defined by ETSI TS 103 172 specifications for PAdES services.
Zoho has partnered with the following TSAs to offer trusted document timestamping:
- Uanataca - for qualified timestamps in EU
- SEIKO - for Japan
- GlobalSign - for all other regions and countries across the globe
How to enable document timestamping
- From the left navigation pane, Click Settings > Account settings > Document timestamp.
- Enable Long Term Archival (LTA) and choose the preferred TSA (Timestamping Authority).

Note:
Because trusted document timestamping is offered via integration with 3rd-party services (TSAs), it consumes Zoho Sign credits. The consumption varies according to the region and the TSA chosen as following:
- GlobalSign - 0.5 credit/stamping activity
- SEIKO - 2 credits/stamping activity
- Uanataca - 0.5 credit/stamping activity
How to check for the timestamp in signed documents
Download the signed document and and click on Signature Panel.
To verify signature timestamp
- Expand the signature properties to view the signature timestamp.
To verify document timestamp
- Right click on the TSA (in this case: Signed by Globalsign TSA for AATL on DSS-SHA384-G5) and select show signature properties.
- Click Advanced Properties to view the timestamp details.