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How do I fix a duplicate Section 18A certificate number?

In short: A certificate number already in use error means the prefix + number + suffix produced a number that already exists. Fix it under Settings → Section 18A Layout by adjusting the Last Certificate No. (and any prefix/suffix) so the next certificate gets a unique number.

Why it happens

ActiveDonor numbers certificates automatically: the full number is prefix + number + suffix (for example PBO-00123-A). The Last Certificate No. is a single running counter that increments for the next certificate. A duplicate number / already in use error means that combination collides with an existing certificate — often because the counter was set behind your real sequence, or a year was mixed into the counter instead of the prefix/suffix (which makes the number won't increment cleanly or jump unexpectedly).

How to fix it

  1. In the top navigation bar, go to Settings.
  2. Open the Section 18A Layout tab.
  3. In the Certificate Numbering section, set Last Certificate No. to one less than the next number you want (the system increments it for the next certificate).
  4. Put any year or text part in Certificate No. Prefix or Certificate No. Suffix (up to 8 characters each) — not in the counter itself.
  5. Click Save Certificate Settings. You'll see Settings successfully saved.

The next certificate you issue uses the corrected, unique number.

💡 Tip: Keep the running counter purely numeric. Putting a year inside the counter is the usual cause of numbers jumping or colliding.

"Already in use" but I can't find another certificate with that number

If the error names a specific number (for example INV-1388) and you've checked but can't find another Section 18A using it, the number is almost certainly held by a revoked or deleted certificate that no longer shows in your normal certificate list. The check that blocks duplicates still counts those hidden records, so the number stays reserved even though you can't see it.

To get past it:

  1. Issue the certificate with a different number — adjust the Certificate No. Prefix/Suffix or the Last Certificate No. so it produces a free number, then issue.
  2. If you specifically need that exact number released, contact ActiveDonor support with the certificate number and the donor's name so we can clear the orphaned record.

📌 Note: Revoking a certificate keeps its number reserved on purpose (for your SARS audit trail), so a revoked certificate's number generally can't be re-used.

  • Certificate settings