Changelog

Version	Date	Description	Created by
1.0	2025-05-20	Created document	Anders Göthberg
1.1		API in production	Anders Göthberg

Introduction

Link to the general step-by-step implementations guide that guides you through setting up a REST API integration towards PayEx Ledger Invoice Service can be found here 

Billing Invoice API presents presents at the lowest level all incoming charges that generated an invoice regardless of presentation in PDF. This can be used for presentation on the company's various applications such as "my pages" or customer service users in the company's own CRM.

Invoice API

Route description

Each resource in the API corresponds to its own route. All routes are structured according to a specific standard, explained below

The below route is an example of a route towards resource3Id, to operate on this resource you must also include the ids of its parent resources in the route.
lf-api.payex.com/billing/{subdomain}/v1/{ownerNo}/resource1/{resource1Id}/resource2/{resource2Id}/resource3/{resource3Id}

Route segment	Description
subdomain	In this part of the API it will be "billing"
ownerNo	The ledger identifier/number at PayEx
resource1Id	Identifier of resource1 (invoices)
resource2Id	identifier of resource2, subresource to resource1 (recurring products or subscriptions)
resource3Id	identifier of resource3, subresource to resource2 (recurring products)

Routes that occurs in examples of this documentation will use the following identifiers

Resource	Identifier
ownerNo	The ledger identifier/number at PayEx
customerNo	Customer number
invoiceNo	Invoice number
subscriptionNo	Subscription number (identifier for subscription)
recurring-products	Recurring products on customer or subscription level

Swaggerfil!!!

Problem types

Problem type (code)	Http status	Description
validation	400	occurs if any of the inputvalidation fails, it is described in the problem which parameter that failed the validation
customer-not-found	404	Customer not found in PayEx Billing
invoice-not-found	404	Invoice number not found in Usage
subscription-not-found	404	Subscription not found on selected customer