- https://github.com/CleverIT/UBL_invoice
- https://github.com/num-num/ubl-invoice
- https://github.com/josemmo/einvoicing
- https://github.com/Invoiced/invoiced-php
- https://github.com/LaravelDaily/laravel-invoices
- https://github.com/paypal/invoice-sdk-php
- https://github.com/Invoiced/invoiced-php
- https://github.com/imosnet/invoice
- https://github.com/byrokrat/billing
- https://github.com/Sylius/InvoicingPlugin