How to get an invoice signed online
Most invoices get paid without anyone signing them. A signature earns its place when you want proof: that the customer accepted the finished work, agreed to the final amount, or received the goods. Here's when to ask for one, what the signed version should say, and how to get it signed on the spot or by link.
Updated October 13, 2026 · 3 min read
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When a signed invoice helps
- Work completion sign-off. The customer confirms the job is done to their satisfaction before you leave the site.
- Final amount approval. Extras, change orders and credits are rolled into one number the customer agrees to.
- Proof of delivery. Someone signs to confirm the goods arrived in good shape.
- Payment terms. An invoice that sets a payment plan or late fee is stronger when the customer has signed it.
- Disputes later. "I never agreed to that" is a short conversation when there's a signature and a timestamp.
What to put on an invoice you want signed
- Your business name and contact details, and the customer's.
- An invoice number, date and the job or order it covers.
- Line items, any approved change orders, taxes and the total due.
- Payment terms: due date, accepted methods, and any late fee.
- A short acceptance line above the signature, such as "I confirm the work described above is complete and I agree to the total due."
- Signature, printed name and date.
That acceptance line matters. A signature next to nothing in particular proves less than a signature under a sentence that says what the customer agrees to.
Is an e-signed invoice valid?
Yes. Under the federal ESIGN Act and state UETA laws, a signature or record can't be denied legal effect just because it's electronic. An invoice signed on a phone works the same as one signed on paper, and it's easier to keep track of.
Get it signed with SignMaster
Each send is an envelope: SignMaster's word for one or more documents going to one or more signers.
- 1
Upload the invoice
Export the invoice from your accounting tool as a PDF and upload it to a new envelope.
- 2
Add the customer
Enter the customer's name and email.
- 3
Place the fields
Add a signature and date signed field under your acceptance line. Or use Approve and Decline buttons, so the customer can approve the total with one tap, which is recorded the same as a signature.
- 4
Sign on site or send
Finishing up at the job? Tap Sign in person and hand over your phone. Otherwise send the link; the customer signs on any device with no account.
- 5
Both get the signed copy
The signed invoice arrives by email with a certificate of completion: who signed, their email, IP address, device and the time.
Send the invoice with the change orders
An envelope can hold several documents. Put the final invoice and any unsigned change orders in one envelope, and the customer approves everything in one sitting.
Questions? Answers.
Does an invoice need to be signed?
Usually not to be paid. A signature is worth asking for when you want proof the customer accepted the work, agreed to the total, or received the goods.
Is an electronically signed invoice valid?
Yes. The ESIGN Act and state UETA laws give electronic signatures legal effect, so a signature on a phone counts like one on paper.
Can my customer approve an invoice without drawing a signature?
Yes. In SignMaster you can place an Approve button. Approving records the customer's agreement, the same as a signature, and it shows on the certificate of completion.
Can I collect a signature on a delivery receipt the same way?
Yes. Upload the delivery receipt or packing slip, add a signature field, and have the recipient sign on your phone with Sign in person.