If your Digital Waste Tracking (DWT) submission is failing with the error "receiver.authorisationNumber must be in a valid UK format", DEFRA is rejecting the receiver authorisation number being sent.
This error occurs even if the number looks correct on screen — DEFRA validates it strictly, and a single incorrect character will trigger it.
Why this error occurs
The receiver.authorisationNumber field must contain the receiving site's waste licence number (EPR format, e.g. EPR/CB3909UF) — not the carrier registration number (CBDU/CBDL format). These are two separate DEFRA registrations and must not be confused. Weighsoft populates this field from two places:
The Permit Number field on the Company record (Lookups → Companies)
The Waste Code field on the Outlet record (Lookups → Outlets)
If either of these fields contains a CBDU/CBDL carrier registration number instead of the site's EPR waste licence number, DEFRA will reject the submission with this error.
Valid waste licence number formats
DEFRA requires the receiver authorisation number to be a valid environmental waste licence number. The format depends on the home nation:
England / Wales: EPR/XXXXXXXX (issued by the Environment Agency)
Scotland: WML/XXXXXXXX (issued by SEPA)
Northern Ireland: LN/XXXXXXXX (issued by NIEA)
Do not enter a carrier registration number (CBDU/CBDL format) in the Permit Number or Waste Code fields — these are for the waste licence only.
Step-by-step: how to find and fix the error
Hover over Administration, click Lookups
Click Companies, then open the company used on the failing transaction.
Check the Permit Number field. This must contain the site's EPR waste licence number (e.g. EPR/CB3909UF). If it contains a CBDU/CBDL carrier number, replace it with the correct waste licence number.
Return to Lookups and click Outlets.
Open the outlet used on the failing job. Check the Waste Code field. This must also contain the EPR waste licence number, not a CBDU/CBDL carrier number.
Correct any field that does not contain a valid EPR waste licence number. Save the changes.
Hover over Administration and click Transactions.
Hover over Administration and click Transactions.
Select the job then click Functions
Click Resend to Digital Waste Tracking.
Hover over Administration and click Digital Waste Tracking to confirm the status updates to Success.
If the number looks correct but submissions still fail
Cross-check the waste licence number against your DEFRA registration certificate or the DEFRA waste permits public register to confirm the exact EPR number for the receiving site. Ensure it is the waste licence number (EPR format), not the carrier registration number (CBDU/CBDL format) — these are two separate DEFRA registrations.