E-signatures for accountants and bookkeepers

Yes. Upload the letter as a PDF, add the people who need to sign, and each gets their own private link. They sign on a phone or a computer with no app, no account and no password, and they never pay. When the last person signs, Pixasign seals the whole file and sends the evidence certificate with it. You send from your computer.

That covers engagement letters, letters of authority, client sign-off on accounts and payroll paperwork: documents your practice chooses to get signed. One thing first. If your practice software already signs engagement letters, use that for them. Pixasign is for the documents outside it, and for practices with no such software. It is free for 3 documents a month.

Check your practice software first

Many practice and tax tools include signing. The table shows what each vendor says on its own page. We read every page below on 20 October 2026 and have not tested any of these products.

If your letters are already signed in one of these, keep them there. Pixasign is a separate service, so a sealed PDF is something you download and file with the client yourself.

What accountants and bookkeepers get signed

These are documents a practice might choose to get signed. Whether any of them must be signed is a different question, and this page does not answer it.

• Engagement letters. The scope, the fee and the terms. Up to 20 people can sign one document, so several directors can sign one letter.
• Letters of authority. The client authorises you to deal with someone on their behalf, or a previous adviser to hand information to you. If you only have a paper form, photograph it and upload the photo. The client then signs it on their phone.
• Mid-year changes of scope or fee. One page the client agrees before the extra work starts.
• Client sign-off on accounts. A PDF of the accounts, with an approval page for the client to sign. What a filing body accepts is set by that body, so check its guidance.
• Payroll and pension paperwork. Covered in its own section below.

Any Word or Excel file needs saving as a PDF first.

Sending an engagement letter, step by step

1. Save the letter as a PDF.
2. Upload it and add the people who sign. Give each one their own signature and date fields.
3. Set a signing order, or turn it off to send to everyone at once.
4. Send it from your computer. Each person gets their own private link.
5. When the last person signs, the file is sealed. You get the signed PDF and the evidence certificate.

A document is one PDF sent for signature, however many of its up to 20 people sign it and however many pages it has. A letter signed by three directors is one document, not three.

Each person is recorded separately on the trail. If one director later says they never saw a new fee, the record shows when their link was opened and when they signed. The guide to signing a PDF online in the UK has more on the mechanics.

What you are left holding afterwards

When the last person signs, the whole file is sealed with one DigiCert timestamp. The seal time comes from DigiCert, independent of us. The time of each earlier step, such as when someone opened the link or signed, is recorded by our server.

Change a byte the seal covers and it breaks; anything added later shows as a change at pixasign.co.uk/check. The seal and its timestamp are inside the PDF, so the file you download carries them.

With the file comes an evidence certificate: who signed, when, from what device, and from what IP address and approximate location. The events are hash-chained, so each one locks in the one before it. The guide to electronic signature evidence in the UK covers the evidence side in more detail.

pixasign.co.uk/check is free, with no account, no sign-in and no card. Drop in a file and it tells you whether Pixasign sealed it and whether it has changed since. It decides that from Pixasign’s own records, so the answer rests on Pixasign. You can hand it to an incoming accountant or a client’s adviser.

Payroll and pension paperwork

If you run payroll for clients, some of the paperwork is yours: the payroll service terms, a client’s instruction to change who approves the payroll, or an authority for you to act for the employer. Pension paperwork your firm chooses to get signed works the same way. Each of these can go out as a one-off PDF, and each counts as one document.

Approving each payroll run is different. If your payroll software already asks the client to approve inside it, keep that there. BrightPay’s page, read on 20 October 2026, says its payroll approval request lets a bureau send clients a payroll summary before the payroll is finalised, with an audit trail of the client’s steps. Each payroll run sent through Pixasign would use one document, so it suits one-off instructions better.

Where Pixasign is the wrong tool

• Re-issuing letters to every client at once. Pixasign has no bulk send and no saved templates. Each document is sent on its own and counts against your monthly allowance.
• Deeds and anything needing a witness. Pixasign does not do witnessing, so these are out. Formalities are a question for whoever drafts the document, not for a software supplier.
• Your profession’s rules. What your professional body expects of an engagement letter, and which forms a tax authority or registry will take with an electronic signature, are questions for their own guidance and your own adviser. Pixasign does not make a practice compliant with anything, and we make no claim that it does.

For the general position on electronic signatures in UK law, read Is an electronic signature legally binding in the UK? The pillar guide, electronic signatures for UK small businesses, covers the rest.

Pricing, for a practice where everyone sends

Partners, managers and bookkeepers may all send paperwork. Per-user pricing means paying for each of them, or sharing one login, which stops the trail saying who sent what. The guide to per-user and flat-fee pricing has the sums.

Pixasign is free for 1 user and 3 documents a month, no card and no time limit. Paid plans have unlimited users and no per-user fee: an account starts with room for 200 active people, raised free on request.

• Starter: £19 a month inc VAT, 50 documents a month.
• Team: £59 a month inc VAT, 200 documents a month.
• Business: £99 a month inc VAT, 500 documents a month.

There is no overage charge and no set-up fee. Billing is monthly with no minimum term, and you can cancel any time from Account. The plan runs to the end of the month you paid for, then the account goes back to Free. Nothing is deleted. At the monthly limit, new sends wait for the 1st or a bigger plan. Allowances renew on the 1st. Clients never pay and never need an account.

The application runs on Hetzner in Nuremberg, Germany, with backups in Reykjavík, Iceland, both in the EEA. Card payments are handled by Stripe. Document files are encrypted at rest (AES-256-GCM). More is on the security page.

Questions

We already sign engagement letters in our practice software. Why would we need this?

You may not, for those. If the letter is signed there and you are happy with what it keeps, leave it there. Pixasign is for the documents outside that flow, such as letters of authority and mid-year changes, and for practices with no such software.

Can two directors sign the same engagement letter?

Yes. Add each director to the same document, each with their own fields, and each gets their own private link. Up to 20 people can sign one document, and the certificate records each person separately.

Can I show when a client agreed a new fee?

The sealed file carries a DigiCert timestamp, applied when the last person signs. The evidence certificate records the earlier steps, such as when each person opened the link and signed, from our server. Whether that is enough for a particular purpose is a question for your own adviser.

Does Pixasign meet my professional body’s requirements?

We make no such claim. It produces a record of who signed what and when. What your body expects is set out in its own guidance.

What happens to our signed letters if we stop paying?

The plan runs to the end of the month you paid for, then the account goes back to Free. Nothing is deleted.