Your documents get a default numbering when you create a business.
Invoices, estimates, orders and delivery notes begin with the number 001.
How to change numbering
Go to Settings - Template design and settings - Numbering and there you’ll find sections for all kind of document types.
You can either select a predefined numbering format or change it to your own. Use the characters YY for the year and NN for document numbers.
Change the Next document number to a number you need for the next invoice and it will receive that number next time you create an invoice.
Examples:
The numbering format NNN creates invoices 001, 002, 003
The numbering format YYYYNNN creates invoices 2019001, 2019002, 2019003
The numbering format INV-YYYYNNNN and next number 580 create invoices INV-20190580, INV-20190581, INV-20190582...
Important notes:
Each of your businesses have their own numbering.
There is only one numbering per business
If you edit, change or click the number which on a document while creating it, the automatic numbering is disrupted. This is useful if you want to create documents with different numbers and don’t want to set it back in Settings each time.
Changing a number directly on an invoice does not affect your overall numbering