Why are my Ukrainian invoices numbered 2026-0001?

When does Deline use yearly numbers?

When the Invoice number prefix in Settings → Business is the default INV- or empty. The hint there says: "With the default INV-, invoices get Ukrainian numbers: № 2026-0001, starting again each calendar year. Any other prefix goes before a running number."

• The year is the year of the invoice's issue date.
• The next number is one more than the highest number already issued in that year.
• Numbers are given when you issue an invoice. A draft has no number yet.

What if I already issued INV-000028?

Then your business keeps its running INV- sequence, so the numbering never jumps in the middle of a year. Numbers already issued never change.

Can I use my own prefix?

Yes. Type any other prefix in Invoice number prefix. Deline then puts it before a running number, as before.

Can I renumber or delete an issued invoice?

No. An issued invoice keeps its number and cannot be deleted. To cancel or correct it, issue a credit note (see Create a credit note for an invoice).