E-signatures
Certificate of completion
A certificate of completion is the evidence record that comes with a signed document: an A4 PDF listing the envelope, how each signer was verified, and every event from sending to completion. The signed document shows the marks; the certificate shows how they got there. It is built from the event log the moment everyone has finished, and it is the file worth keeping alongside the contract.
Section one: the envelope
Seven rows. The envelope identifier in a monospaced face so it can be quoted accurately. The moment it was sent and the moment it completed, both to the second in UTC. How many signers there were. The certification applied, named as an algorithm rather than a vague claim of security. Then two hashes: the document as it was uploaded, and the document once every signature had been stamped into it, taken before certification. Neither figure is a checksum of the file you download, because certification changes the bytes after both were taken. They record what the document was at those two moments, not a value to compare a download against.
Section two: a block per signer
Each signer gets their name and address on a shaded band, then six indented rows. How they were verified, written out as email link, email link plus access code, or email link plus emailed one-time code. When they signed. Their IP address, or not recorded if none was captured. When they accepted the consent and which version of it. The hash of the document at the instant they signed, which is not the same as the final hash when several people signed in turn. And the hash of their signature image.
Section three: the event log
The whole audit trail printed as a table with four columns: sequence number, the timestamp in UTC, the event in plain words, and the email of whichever signer it belongs to. Rows alternate shading and continue across pages, and a continuation page redraws the column headers rather than leaving a stack of unlabelled numbers. Pages carry a footer reading Certificate of completion with page x of y at the other end.
When it is built, and why the order matters
It is built after the last signature is stamped and before the document is certified, using the hash of the fully stamped file. That sequence is not arbitrary. Certification at document modification level one forbids anything being appended afterwards, so if the certificate is going to live inside the signed PDF it has to be added first. Getting that order wrong would produce a file that readers report as altered.
Inside the document, or beside it
By default the signed PDF stays clean and the certificate is a separate download, which suits an agreement that will be printed or forwarded. A checkbox in the prepare panel, Include certificate of completion in the signed PDF, appends its pages to the end instead, so the evidence travels with the document. Either way it is also written as its own file and offered as its own button on the status page.
How it works, in three steps
Step 1
Decide before sending whether it goes inside
The checkbox sits under the Sign in order switch on the prepare panel, and is off by default.
Step 2
Wait for everyone to finish
The certificate is built from the completed event log, so it does not exist until the last signature has landed.
Step 3
Download it from the envelope
A Certificate button appears next to Signed document on the status page once the envelope is complete.
The full walkthrough with screenshots is in the guide Send a PDF for e-signature.
Limits worth knowing
- It only exists once every signer has finished. A declined or expired envelope never produces one.
- The layout and wording are fixed. There is no branding, logo or custom text.
- It records IP addresses but not geolocation, device names or anything derived from them.
- The whole event log is printed, so an envelope that was chased many times produces a longer certificate.
Questions people ask
Is the certificate itself covered by the signature?
Only when you tick Include certificate of completion in the signed PDF before sending. Its pages are then appended before certification, so the certification covers them along with the document. As a standalone download it is a plain PDF with no signature of its own, which is fine for filing but is not tamper evident on its own.
Why are there two different document hashes?
One is the file as you uploaded it, before anybody signed. The other is the file once every signature was stamped in, taken just before certification. Each signer's block also carries the hash as it stood when they personally signed. None of them equals the hash of the certified PDF you download, so do not use them as a download checksum.
Can I add my company logo to the certificate?
No. The layout and wording are fixed, with no logo, colour or custom text. That is deliberate: a document of record is more useful when it looks the same on every envelope, and a reviewer comparing two certificates can find the same row in the same place. Put your branding on the document being signed instead.
Do signers receive a copy of the certificate?
Every recipient and the sender get the completion email with the certified PDF attached. If you ticked the include option, the certificate pages are inside that attachment. If you did not, the certificate is a separate download on the envelope's status page, so send it to anyone who needs it yourself.
What does the certificate record about each signer?
It records the evidence rather than proving identity by itself. For each signer it prints the verification method, the IP address, the consent acceptance with its version, the signing time and the hashes. How much that evidence weighs depends on the verification you chose: an access code or an emailed one time code adds a second factor beyond the email link.
How long is a certificate of completion?
Usually one A4 page for two signers with an ordinary event log. It grows with the number of signers and events, since every open, verification, resend and signature is a row in the event log, and a continuation page repeats the column headers. An envelope that was chased several times will run longer than one that was signed on the first invitation.
Make your own signing flow
The button opens the generator with this use case already described. Change the wording to match yours, generate, then edit anything you like.
Send a document for signingRelated pages
Electronic signing consent
A single line above the submit button asks the signer to agree that signing electronically counts. It is the least visually interesting part of the flow and one of the more useful things kept afterwards.
Download the signed document
Three different files come out of one envelope, and knowing which is which matters when somebody asks you for the contract six months later. Two of them exist only after everyone has signed.
Tamper proof signed PDF
Nothing makes a file impossible to alter. What a certifying signature does is make an alteration impossible to hide, which is the useful property. Any editor can change the number on page two; none can do it without the file announcing it.
More finished work of this kind is on the e-signature examples hub.
Written and checked by the OneCraft team. Last checked .