Question 1

What is a good invoice number format?

Accepted Answer

A short prefix, the year and a number padded with zeros, for example INV-2026-00001. It sorts in order, shows the year at a glance and leaves room for thousands of invoices.

Question 2

Do invoice numbers have to be in sequence?

Accepted Answer

In most countries, yes: each invoice needs a unique number and the numbers should follow on without gaps. Tax authorities, including the UAE Federal Tax Authority for tax invoices, expect a sequential number.

Question 3

Can I start invoice numbers at a number other than 1?

Accepted Answer

Yes. Starting at, say, 1001 is common. What matters is that every number is used once and the series keeps going up.

Question 4

Should I restart the numbering every year?

Accepted Answer

You can, as long as the year is part of the number so INV-2026-00001 and INV-2027-00001 stay different. If the year is not in the number, keep counting up.

Question 5

What if I cancel an invoice?

Accepted Answer

Do not reuse or delete the number. Mark the invoice cancelled, or issue a credit note, so the series has no unexplained gaps.

Invoice number generator

Questions

Never pick the next number by hand again