---
title: "How to sign client contracts and statements of work · Attest"
description: "Get master agreements, statements of work and change orders signed in order, tie each SOW to its contract, and prove which version a client approved."
url: https://attest.datahubz.com/use-cases/client-contracts-and-statements-of-work
updated: 2026-10-12
---

[Attest](https://attest.datahubz.com/)/[Use cases](https://attest.datahubz.com/use-cases)

# How to sign client contracts and statements of work

Sign the master agreement once, then send each statement of work and change order as its own document that names the agreement it belongs to, so every scope and price a client approved has its own signatures, date and fingerprint. With Attest, each client signer approves with a passkey only they control, every document is end-to-end encrypted, and the sealed copy verifies for free, even without Attest, on the Signing plan at $5 a month for 20 documents.

By DataHubz · Updated October 12, 2026 · 7 min read

## The documents behind a client relationship

Most businesses that sell services work from a small set of documents, and each one approves something different:

- **Master services agreement (MSA):** the terms that last for the whole relationship, such as payment terms, confidentiality, ownership of the work and liability.
- **Statement of work (SOW):** one per project, with its scope, deliverables, timeline, acceptance criteria and price.
- **Change order:** a change to one statement of work's scope, price or dates.
- **Renewal or amendment:** new dates, rates or terms for the master agreement.

Signing each one as its own document gives every approval its own signatures, date and fingerprint. With Attest, each is a PDF of up to 8 MB that you upload, and each can have up to 20 signers.

## Tie each statement of work to its contract

When an Attest document is complete, its signed copy carries the agreement's verification code (ATT-XXXX-XXXX) on each signature stamp and at the foot of every page of the document, and that code opens the agreement's certificate. Use it to link your documents:

1. Send the master agreement first.
2. When it's complete, copy its verification code from the signed copy into each statement of work, for example: "This statement of work is governed by the Master Services Agreement with verification code ATT-XXXX-XXXX."
3. Copy each statement of work's code into its change orders the same way.

Anyone who reads a statement of work can then type the code at attest.datahubz.com/verify to open the certificate of the agreement it refers to. If that agreement's certificate is private, they are told it exists and is private.

## Get the right people to sign, in order

On the client side, a statement of work often needs two signatures: the person who owns the budget, and someone in legal or procurement. The **New agreement** form handles that:

- **Signing order**, set to **In order**: list the client's signers in the order they should sign. Only the current signer is emailed, the next one when the previous one signs, and anyone who opens their link early sees "Not your turn yet".
- **Add me as a signer (sign in-app, no email):** with **In order**, choose **Last** to countersign after the client, or **First** to sign before it goes to them.
- **Fields:** a signature for each signer, initials on the pages that matter, a date signed and a full name field, which fill in by themselves, and text fields with a label such as "Purchase order number", which can be optional.
- **Expires (optional):** a proposed statement of work that isn't signed by a date closes, and every party is emailed.
- **Reminders:** every 3 days by default, or every day, every 2 days or every week, sent only to the signer whose turn it is and counted from the start of their turn, at most 5 times.

## Which version did the client sign?

Contracts go through rounds of changes, and the risk is a signature on one draft while you work from another. With Attest, each signer's passkey signs a statement that names the document's **fingerprint** (a SHA-256 hash, a short code calculated from the file's contents) and everything that signer entered, so every signature points at one exact file, and every party downloads the same sealed copy. A **passkey** is a cryptographic key only the signer controls, unlocked with Face ID, Touch ID, Windows Hello or the device PIN.

If the client sends back a marked-up version, send that version as a new document. If you void the earlier one before anyone has signed it, it goes back to your allowance. The guide on [making sure every party signed the same version](https://attest.datahubz.com/guides/every-party-signed-same-version) goes further.

## When a scope dispute comes

Six weeks into a project, a client says a feature was always in scope, or questions an invoice for extra work. The signed statement of work and change order each show:

- **What was approved:** the scope and price in the document, with each signer's entries.
- **Who approved it:** each signature was made with a passkey registered to that signer's email address, and Attest confirms control of that address and the passkey, not a government ID.
- **When:** the signing time is part of what each passkey signs, and the completed agreement is anchored on Horizen, a public blockchain, whose block time shows when.
- **That nothing changed:** change one byte of the document, of any signer's entries or of the signed pages, and verification fails.

Every party holds the same sealed PDF, with the full evidence, the original document and a standalone verifier attached inside. The client's finance team, a mediator or a lawyer can check it for free, with no account, at attest.datahubz.com/verify, or with the open-source verifier attached inside it, which runs in any browser even without Attest and checks each signer's passkey signature, the original document, the pages you see and Attest's anchored record on Horizen.

## Keep the client's information private

A statement of work often holds the client's own information: their systems, their plans, their numbers. Most e-signature services describe encryption in transit and at rest, and describe no end-to-end mechanism, so their systems can decrypt the documents they store. We compared 21 e-signature services in October 2026, Attest and 20 others, and [Attest was the only one](https://attest.datahubz.com/compare/which-e-signature-services-can-read-your-documents) that end-to-end encrypts every document, for every signer, by default.

**End-to-end encryption** means the document is encrypted in your browser before upload and decrypted only in the browsers of its parties. Attest stores it only as ciphertext it can't read. If a client's security team asks how their documents are handled, that is the answer.

Attest does see the information around a document: its title, file name, size and type, your note, the email addresses of your account and of the signers, the signers' names, where fields are placed and when each step happened. By default, each agreement also has a public certificate that shows anyone with its link details such as the title, the file name and each signer's name and signing time, never the document. For client work, use plain titles such as "SOW 4" and choose **Private** when you send, so only the parties see the certificate.

## What it costs

A firm that signs 2 new master agreements, 4 statements of work and 6 change orders in a month sends 12 documents. That fits the Signing plan: $5 a month for 20 documents, or 25 cents a document when you use all 20. Your first 2 documents are free, in total, and your clients never pay.

| Service (as published October 11, 2026) | Monthly billing                                       | Allowance                                               |
| --------------------------------------- | ----------------------------------------------------- | ------------------------------------------------------- |
| **Attest, Signing plan**                | **$5 a month**                                        | 20 documents a month                                    |
| Zoho Sign Standard                      | $12 per user a month ($10 per user billed annually)   | 25 envelopes per user a month                           |
| Adobe Acrobat Standard                  | $24.99 a month ($14.99 a month on an annual plan)     | Transactions listed as unlimited, up to 10 signers each |
| DocuSign Standard                       | $45 per user a month ($30 per user on an annual plan) | Up to 10 envelopes per user a month on monthly billing  |

At 12 documents a month on monthly billing, DocuSign Standard's 10 envelopes per user would need a second user or pay-as-you-go envelopes. Signing a contract a client sends you through Attest is free; signing their own PDF with **Sign a document yourself** uses one of your documents.

## Send a statement of work, step by step

1. Go to attest.datahubz.com/sign, click **Start free**, sign in with your email and set up your signing key once, with a passkey and a recovery phrase, on the **Security** page.
2. Click **New agreement**, give it a plain **Title**, such as "SOW 4", and click **Attach the document to be signed (PDF, up to 8 MB)** to choose the PDF.
3. Under **Signers**, add the client's signers in order. Check **Add me as a signer (sign in-app, no email)**, pick **In order** under **Signing order**, then choose **Last**.
4. Under **Verification**, choose **Private**. Click **Next: place the fields**, place each signer's fields, and click **Create and send**.
5. The first time a client signer uses Attest, Attest emails you once they have set up their key: click **Unlock it for …** in that email (or open the agreement in Attest), confirm, and approve with your passkey. Your browser releases it to them, never Attest.
6. When it's your turn, the document moves to **Action needed** (you aren't emailed): click **Sign** on its row and approve with your passkey. When everyone has signed, download the sealed copy.

## Questions people ask

Is a client contract signed electronically binding?

Electronic signatures are recognized for most agreements in the United States (the ESIGN Act and UETA) and the European Union (eIDAS). Some documents, such as wills or certain notarized deeds, have special rules in many places: check yours. In the EU, an electronic signature "shall not be denied legal effect and admissibility as evidence in legal proceedings solely on the grounds that it is in an electronic form or that it does not meet the requirements for qualified electronic signatures" (eIDAS Article 25(1)). This is general information, not legal advice.

Do my clients need an Attest account?

No. Each client signer opens their private link and sets up a passkey, with no account, no password and nothing to pay. The first time someone signs with Attest, you release the encrypted document to them from Attest's email, approving with your passkey.

The client wants changes after signing. What do I do?

A completed document stays exactly as it was signed, so put the change in a new document: a change order for a statement of work, or an amendment for the master agreement. Write the earlier document's verification code into the new one, so it is clear which document it changes.

Can I prove to a new client or an auditor that a contract is in place, without sharing it?

Yes, if you signed it. On a completed document, Share proof creates a zero-knowledge proof that you, or you and a named co-signer, signed an agreement, and the date it was completed. The recipient sees the email addresses, the completion date, and that the proof is valid and where its record is anchored, never the document, its title or its terms.

## Sources

1. [Zoho Sign pricing](https://www.zoho.com/sign/pricing.html), Zoho, read October 11, 2026
2. [Adobe Acrobat plans and pricing (Individuals tab)](https://www.adobe.com/acrobat/plans.html), Adobe, read October 12, 2026
3. [Acrobat Sign transaction limits (help page last updated March 11, 2025; Internet Archive copy of October 9, 2026)](https://web.archive.org/web/20261009122456/https://helpx.adobe.com/sign/web/system-level-resources/transaction-limits.html), Adobe, read October 11, 2026
4. [Docusign eSignature plans and pricing](https://ecom.docusign.com/plans-and-pricing/esignature), Docusign, read October 11, 2026
5. [Docusign platform safety](https://www.docusign.com/safety/platform-safety), Docusign, read October 11, 2026
6. [Adobe Acrobat Sign Security Overview (June 2026)](https://www.adobe.com/cc-shared/assets/pdf/trust-center/ungated/whitepapers/doc-cloud/adobe-acrobat-sign-security-overview.pdf), Adobe, read October 11, 2026
7. [Dropbox Sign features](https://sign.dropbox.com/features), Dropbox, read October 11, 2026
8. [PandaDoc AI policy](https://support.pandadoc.com/en/articles/13794735-pandadoc-ai-policy), PandaDoc, read October 11, 2026
9. [15 U.S.C. Chapter 96, Electronic Signatures in Global and National Commerce (United States Code, 2023 edition)](https://www.govinfo.gov/content/pkg/USCODE-2023-title15/html/USCODE-2023-title15-chap96.htm), U.S. Government Publishing Office, read October 11, 2026
10. [Uniform Electronic Transactions Act (1999), final text with comments](https://www.uniformlaws.org/HigherLogic/System/DownloadDocumentFile.ashx?DocumentFileKey=1b1ffc6b-9b6a-35a4-2a83-7b4d5c0f77a7&forceDialog=0), Uniform Law Commission, read October 11, 2026
11. [Regulation (EU) No 910/2014 (eIDAS), consolidated text](https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX:02014R0910-20241018), EUR-Lex, Publications Office of the European Union, read October 11, 2026

## Read next

- [How to make sure every party signed the same version](https://attest.datahubz.com/guides/every-party-signed-same-version)
Avoid mismatched drafts: lock the final version, send one document to every signer, and confirm afterward that every signature names the same fingerprint.
- [How to collect signatures in a set order](https://attest.datahubz.com/how-to/collect-signatures-in-order)
Send one document to several people who sign one at a time, in the order you set: each is emailed when it's their turn. Step by step, with tracking.
- [E-signatures for freelancers and consultants](https://attest.datahubz.com/use-cases/freelancers-and-consultants)
Get contracts, statements of work and change orders signed with proof for scope and payment disputes, your rates kept private, for $5 a month.
- [Document signing](https://attest.datahubz.com/sign)
Electronic signatures with a passkey: no account or password for signers, documents encrypted in the browser, and a signed copy anyone can verify.

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Source: https://attest.datahubz.com/use-cases/client-contracts-and-statements-of-work