Electronic Invoice Integration

Electronic invoicing is usually approached as a formatting requirement and turns out to be something considerably harder. Documents must be prepared to an exact specification, signed cryptographically, and submitted reliably. Acknowledgements and rejections arrive asynchronously — sometimes long after the business has moved on — and every submitted document must reconcile back against the business record. A system that handles the happy path and not the exceptions creates a compliance problem rather than solving one.

We built the integration around the failure cases first. Document preparation is generated from the business system rather than re-entered, so the two records cannot diverge. Cryptographic signing and token handling are implemented as security-critical components with proper credential management. Submission tracks state through acknowledgement or rejection, and unresolved documents surface in an exception report rather than disappearing. The integration was designed to be maintained as the specification changes, because it does.