Definition
A digital signature on an invoice or estimate is an electronic image or cryptographic mark that identifies who issued or approved the document. On invoices it adds a personal, professional touch; on estimates and quotes a client's electronic signature records their acceptance of the price and terms.
Also called: Electronic signature, E-signature
Digital signature in practice
An image of a handwritten signature is an electronic signature in the simple sense and is acceptable for most invoicing purposes. Cryptographic digital signatures that verify the document has not been altered are required only in specific regulated contexts.
Frequently Asked Questions
Do invoices need to be signed?
No. Invoices are valid without a signature in almost every country. Signatures are more useful on quotes and contracts, where they record the client's acceptance.