How to Sign a Contract Addendum or Amendment Online (Free)

To sign a contract addendum electronically, open the addendum (PDF or Word) in a free signer such as Docsigns, draw, type or upload your signature, drop it on the signature line with the date, download the signed PDF and send it back to the other party. The part that matters more than the signing is checking that the addendum clearly names the original contract and that every party who signed the original signs this too.

An addendum (or amendment) changes or adds to a contract that already exists: a later move-out date on a lease, a new payment schedule on a freelance agreement, an extra deliverable in a service contract. Because it changes terms you already agreed to, it deserves the same care as the original. Here is how to read it, sign it and keep a clean record, without printing anything.

Addendum or amendment: does the difference matter for signing?

People use the words loosely, and for signing purposes the process is identical. Strictly speaking:

	Addendum	Amendment
What it does	Adds something new to the contract	Changes or removes existing terms
Typical example	A pet clause added to a lease	Rent changed from one amount to another
When it is made	At signing or later	After the original is signed
Who signs	The same parties who signed the original contract (or people authorised to sign for them)

Whatever the title says, what makes it work is the content: it should identify the original contract, state the change clearly, and be signed and dated by the parties.

Before you sign: a five-point check

An addendum is usually short, which makes it easy to sign without reading properly. Spend two minutes on these:

1. It names the original contract. Look for the title, the date of the original agreement and the names of the parties, for example "This addendum amends the Lease Agreement dated 1 March between…". Without that link it is unclear what it changes.
2. The change is specific. "Clause 4 is replaced with the following" is clear. "Payment terms are updated" is not.
3. Everything else stays the same. Most addenda include a line saying all other terms of the original contract remain in force. Check nothing else has been quietly changed.
4. There is an effective date. Does the change apply from signing, from a specific date, or backdated? That matters for rent, fees and deadlines.
5. The right people sign. If two tenants signed the lease, both should sign the addendum. If a company signed, the person signing should be authorised to sign for it.

If anything is unclear, ask the other party to fix the wording before anyone signs. Editing a signed document afterwards creates exactly the confusion an addendum is meant to avoid.

How to sign the addendum online, step by step

1. Save the file. If it arrived by email, download the attachment to your phone or computer. It can be a PDF, DOC or DOCX.
2. Open the signer. Go to docsigns.online and upload the addendum. No account is needed.
3. Create your signature. Draw it with a mouse, trackpad or finger, type your name in one of six cursive fonts, or upload a photo of your handwritten signature. Choose a pen colour; black or blue is the usual choice for contracts.
4. Place it. Drag the signature onto the signature line and resize it so it fits. If the addendum has several pages with lines for initials, you can place a signature or initials on any page.
5. Add the date. Place a date next to your signature and pick the format that matches the document.
6. Download the signed PDF. The output has no watermark.
7. Send it back using the same channel the addendum came through, so the conversation history stays together.

The how it works page shows the same three-step flow with screenshots if you want to see it before you start.

When more than one person has to sign

Docsigns does not send signing requests or route a document between people; each person signs the file themselves. The simple way to collect several signatures is a relay:

1. The first person signs and downloads the PDF.
2. They send that signed PDF to the next person.
3. The next person uploads the already-signed PDF, adds their own signature on their line, downloads it and passes it on.
4. The last person to sign sends the fully signed copy to everyone.

This keeps one document with all signatures on it, rather than several copies each signed by one person. Agree in advance who signs last and who circulates the final copy.

A note on privacy for PDFs and Word files

If your addendum is a PDF, Docsigns signs it inside your browser and the file is not uploaded. If it is a Word document (DOC or DOCX), it is first converted to PDF on a server, and then signed. If the addendum contains information you would rather not send anywhere, ask for it as a PDF, or export it to PDF yourself from Word before signing.

Common mistakes with addenda

• Signing different versions. If the wording was edited during negotiation, make sure everyone signs the final version. Compare the date or version number in the footer before signing.
• Handwritten changes on the original instead. Crossing out a clause on the signed contract and initialling it is harder to read later than a separate, clearly worded addendum.
• Leaving the date blank. An undated addendum makes it unclear when the change took effect. Always place a date next to your signature.
• Only one side keeping the final copy. Whoever signs last should send the fully signed PDF to every party, not just reply "done".

Is an electronically signed addendum valid?

For most everyday agreements, yes. Electronic signatures are generally accepted under laws such as ESIGN and UETA in the United States and eIDAS in the European Union, and most countries have equivalent rules. That covers the typical addendum to a lease, a freelance or service contract, an employment agreement or a purchase order.

There are exceptions. Some documents, such as property transfers, wills and certain financial instruments, may need a wet-ink signature, witnesses, a notary or a qualified electronic signature backed by a certificate. A useful rule of thumb: if the original contract needed one of those, assume the addendum does too, and check before signing. Also check the original contract itself; some contracts say amendments must be made in a particular way.

Docsigns produces an electronic signature, not a qualified digital signature, and it does not create an audit trail. This is general information, not legal advice; for a high-value or disputed agreement, ask a lawyer.

After signing: keep a clean record

• Store the addendum with the original contract. Save both in the same folder, and name the files so the order is obvious, for example "Lease 2026 – original" and "Lease 2026 – addendum 1 – rent change".
• Keep the email or message in which the fully signed copy was sent. It shows when and how everyone received it.
• Number your addenda if there may be more than one, so a later reader knows which change came first.
• Read the contract and addendum together when a question comes up. The addendum overrides only the parts it mentions.

Need to sign the original contract or another document later? The Docsigns blog has guides for leases, offer letters, NDAs, invoices and more.