How do I turn off/on auto generation of invoice numbers?

To turn on/off auto generation of invoice numbers, click on the tiny settings button right next to the field ‘Invoice number’. Here you can choose to either enable or disable auto generation. This can be done while converting an estimate into an invoice, or later on by going to a created invoice and clicking on ‘Edit’. For imported invoices, we provide an option to enable or disable auto generation before the upload.