Customers & sales

Customer numbers

Give every new customer the next number automatically, with your own prefix.

Last updated 21 October 2026 · More in Customers & sales

Each company can have its own customer numbers. Every new customer gets the next number by itself. A number is never given twice and never used again after it was released.

Where to find itSecurity / Admin → Settings → Customers, section Customer no.

Set it up

  1. Enter a Prefix, for example C-.
  2. Enter the Next number. It must be higher than the highest number already used.
  3. Set the Digits, which pads the number with leading zeros.
  4. Check the preview line Next number, then select Save.

Where the number appears

  • The customer list, its search and its sorting.
  • The header of the customer file and the customer form.
  • Invoices, credit notes and quotes as PDF.
  • The customer area in the shop.

Numbers are assigned in every route: the form, import, registration, converting a lead and the app. Leave the field empty and the next number is used.

Existing customers

They keep their current number. Nothing is renumbered unless you decide to. Under Convert existing customers you can choose to Keep today's number (add prefix) or Renumber from the next number (by creation date). Select Show preview first, then Convert now. Documents already issued stay unchanged. Undo last conversion reverses it.

ImportThe customer import assigns new numbers. It cannot yet carry over old numbers from your file.
Was this article helpful?

Nothing is tracked — the buttons only open a message so you can tell us what was missing.

Related articles

idup

All-in-One Accounting, Payroll & Digital Finance — Simplified

Copyright © 2026 - IDup. All rights Reserved.