Error code 5012 is the most common error and usually appears when information in a subcontractor’s record is missing or incorrectly formatted. Here’s how to resolve it:

Common Causes

- Missing UTR or National Insurance Number:
 Check that each subcontractor has a UTR (Unique Taxpayer Reference) or a National Insurance number recorded.

- Incorrect Details or Formatting:
 Make sure there are no invalid characters in the subcontractor’s name or other details.  
 - If a subcontractor has double middle names, use a hyphen between them instead of a space (e.g. “John-Paul” instead of “John Paul”).

What to Do if the Subcontractor Has No UTR

A UTR is not mandatory. However, if you don’t have the UTR for a subcontractor, you must set their Tax Payment Status to Unmatched (30%)

Steps:
1. Open the ‘PAYMENTS’ tab in CIS
2. Find the relevant subcontractor and open their payment for the period you are submitting the CIS 300 return.
3. Either: Enter the missing UTR into the SUBCONTRACTORS - Basic Details section,
OR Change the Tax Payment Status - in this same section to ‘Unmatched (30%)’.

4. Save your changes.

Summary

• Always check for complete and correctly formatted subcontractor details.
• If you are missing a UTR, set the status to ‘Unmatched (30%)’ for that subcontractor.
• Save all changes before resubmitting the CIS 300 return.

Back on the Payments screen, ensure that the rate on the right side of the screen says 'Unmatched':

Finalise the subcontractor's payment and submit the CIS300 once more.