Invoice Configuration
This page describe setup options for customers invoices module (Menu Home - Setup - Modules - Invoices)
Numbering module for invoices
Every company use different numbering rules for its invoices. For this, Dolibarr propose several sub-module that implement different rules. Only one sub-module can be used. If there is no numbering sub-module that match you own rule, you can still build your sub-module or hire a developer to build it. Warning, to be compliant with accounting rules, your numbering module must include in returned value a number that is each time increased and with no hole (no reset to 0 between month).
Invoice documents models
Also, you can use several predefined invoices document models. To build an invoice using a particular model, go on invoice tab and, in the array "Documents" at the bottom of the page, choose the model and click on "Build" to generate the document for invoice from this model.
All models are available in directory htdocs/core/modules/facture but to have them active and to be able to select them to build documents, you must first activate them on the invoice module setup page.
To see models available by default, follow this link apercuDesModeles
Payment mode to show on invoices
To complete
Other options
Invoice date
If this option is activated, the invoice date will be automatically set to the validation date when invoice is validated. Without this option, you are free to put the date you want.