Signature Match
API — Fast & Secure

How the signature matching API is used in practice

The signature matching API compares a signature against a reference signature and returns a similarity result. It is used wherever a signature on paper still carries legal or financial weight: cheques, loan documents, account mandates and physical forms that are scanned into a digital process. This section explains how teams deploy the signature matching API.

What it compares

The signature matching API looks at the shape and structure of two signature images and reports how similar they are. It does not need to know what the signature says; it compares how it is written. The reference signature usually comes from an earlier, trusted record, such as the signature captured when the account was opened.

Getting good input

• Crop the signature tightly before calling the signature matching API, so other text and stamps are not included.
• Use a reasonably high-resolution scan; faint or low-quality images reduce how much the comparison can rely on.
• Keep a clean reference signature on file and update it if the customer formally changes their signature.

Turning a score into a decision

Like any matching check, the signature matching API produces a score that needs a policy around it. Set a threshold above which signatures are accepted automatically, a range that goes to a trained reviewer, and a level below which the document is rejected or the customer is contacted. Natural variation between someone's signatures is normal, so the review band matters as much as the automatic one.

Where teams use the signature matching API

Banks use the signature matching API in cheque processing and for mandate forms. Lenders use it on signed loan agreements. Insurers use it on claim and proposal forms. In each case it lets a human reviewer focus on the small number of documents that really need attention, instead of comparing every signature by eye.

Limits to plan for

A skilled forgery of a simple signature can look very similar to the real one, so the signature matching API should be one signal among several for high-value transactions. Pair it with identity checks on the person presenting the document, and keep the original images so any decision can be reviewed later.