Contract Signature Forms

Invoice Signature Form

Invoice approval form with billing details, line item summary, total due, and client authorized e-signature.

Use online on

  • Invoice number and date fields
  • Line items with quantity and amount
  • Optional payment collection after signing

Quick answer

An invoice signature form sends clients a clear breakdown of charges and collects their authorized signature before you finalize billing — reducing disputes on custom work and change orders.

About this template

Freelancers and agencies often need more than a PDF invoice — they need proof the client approved scope changes or final totals. This form presents invoice metadata, itemized charges, tax, and total due. The client signs to authorize payment, and you receive a timestamped record.

Pair the form with a payment field if you want sign-and-pay in one step. Otherwise, use it as an approval gate before sending wire instructions or charging a card on file.

Typical fields

  • Invoice number and issue date
  • Vendor / sender business name
  • Client company and contact name
  • Project or PO reference
  • Line item description, quantity, unit price
  • Subtotal, tax, and total due
  • Payment terms and due date
  • Authorization statement
  • Client authorized e-signature and date

Best for

  • Freelance project billing approval
  • Construction and trade change orders
  • Agency pass-through expense sign-off
  • B2B custom manufacturing quotes
invoicebillingapproval

Common questions about this form

Why add a signature to an invoice?
A signed invoice creates a record that the client reviewed and approved charges before payment — useful for custom projects, change orders, and B2B billing where purchase orders require explicit authorization.
Can clients pay after signing?
Yes. Connect Stripe or PayPal on forms.app or Jotform so clients sign the invoice and pay in one flow. Alternatively, use the form for approval only and send payment instructions separately.
Is this a replacement for accounting software?
No. This form handles approval and signature capture. Export signed PDFs to your accounting system or attach them to records in QuickBooks, Xero, or similar tools.