Let's run the numbers.

You're charging for

General invoice details

Your invoice number should be a logical, sequential number (e.g. 2023-001).

If you don't charge VAT, set it to 0%.

Invoice specifications

Describe how many hours you worked on what. Multiple entries will be split up on the invoice.

// line 1

0 Hours * 0 * 0%

= €0.00