Countersign a signed PDF and make it fully executed

How to countersign a signed PDF, step by step

1. Compare it with what you agreed. Before anything else, read the returned PDF against the last version you negotiated: party names, prices, dates, notice periods, and every page. Files get re-exported, pages go missing, and occasionally a clause changes between the draft and the "final". Your countersignature accepts the document in front of you, not the one you remember.

2. Find out what kind of signature they used. A drawn, typed or scanned signature is just part of the page, and countersigning next to it changes nothing. If they signed through DocuSign, Adobe Acrobat Sign or with a digital ID, the file may carry a cryptographic seal that breaks when the PDF is saved again as a new copy. The free checker linked above tells you which you have in a few seconds. If it finds a seal, the cleaner route is usually to sign inside the platform that sent the file.

3. Sign in your block, not theirs. Contracts label each block — Client and Contractor, Landlord and Tenant, Company and Employee. Place your signature on the line in yours. If you sign for a business, the line usually starts with "By:" and has room for your printed name and job title; fill both, so it's clear you signed for the company rather than personally.

4. Date it. Write the date you actually sign. Many agreements give an effective date of their own; others take effect when the last party signs, which as the countersigner is you. If the contract asks for initials beside handwritten changes or on every page, add those too.

5. Send the executed copy to everyone. Download the finished PDF and email it to all parties as an attachment rather than a link that expires. A subject line such as "Fully executed agreement — [name] — [date]" makes it easy to find later. Keep the copy they sent you as well.

Whose block, which date: four common cases

Four everyday cases show where the second signature goes and which date it gets. Leases and mutual NDAs follow the same pattern.

A client returns a signed statement of work: as the agency or freelancer, you sign in the block for Contractor (or Consultant, or Agency, whatever the SOW calls you) and date it the day you sign, while the project dates written into the SOW stay as they are.

A supplier sends back its signed agreement: as the buyer, you sign on the "By:" line of your company's block, print your name and job title on the lines below, and add today's date, so the record shows the company signed through you rather than you personally.

A candidate returns a signed offer letter: someone with authority to sign for the employer countersigns in the company's block, dated the day they sign, which is separate from the start date written in the letter.

The agreement says it may be signed in counterparts: you can either countersign the copy they signed or sign a separate identical copy and exchange it, and in both cases each signer dates their own signature.

What “fully executed” means

A contract is fully executed once every party who is meant to sign has signed. Until then you have a partly signed document: one side is on record agreeing, the other isn't yet, and the first signer may be left unsure whether there is a deal. That's why countersigning promptly matters — and why the countersigner usually sends the final PDF round.

Whether an agreement binds anyone before both signatures are on it depends on the law and on the wording. Some offers say they only become binding when countersigned; in other cases a deal can exist from emails or conduct. If a lot rides on the exact moment, the contract's own wording — or a lawyer — has the answer, not the PDF.

Is a countersignature added to a PDF valid?

In most everyday situations, yes. In the United States the federal ESIGN Act says a signature or contract may not be denied legal effect solely because it is electronic, and the EU's eIDAS Regulation says the same about electronic signatures in court. For England and Wales, the Law Commission's 2019 report found that a document can be validly executed with an electronic signature as long as the person signing means it to authenticate the document and any formalities the law requires are complied with.

There are exceptions. ESIGN excludes wills, adoption, divorce and other family-law matters, and court documents, among others, and deeds in England still need a witness physically present. A signature placed with this tool is a simple electronic signature — an image of your signature on the page — which suits ordinary commercial agreements, not documents that the law or the other party requires to be signed in a specific form.

If you spot a problem before countersigning

Don't fix it in the PDF yourself. Changing text in a document the other side has already signed means they signed something different from what you're returning. Reply instead with what's wrong and ask for a corrected version; they sign that one and you countersign it. Small agreed corrections can also be handwritten, with both parties initialling beside them — ask before you do it.

Sources

• ESIGN Act, 15 U.S.C. § 7001 — validity of electronic signatures and contracts
• ESIGN Act, 15 U.S.C. § 7003 — documents the Act does not cover
• eIDAS, Regulation (EU) 910/2014 — Art. 25 on the legal effect of e-signatures
• Law Commission — Electronic execution of documents (2019)
• Adobe Help — Permissions and limitations of signed PDFs