10xxx · Message header
CESOP error 10050
“Wrong format of the MessageRefID”
Caught before you file
What it means
The MessageRefId is not in the required format. Every CESOP reference is a UUID version 4.
Why files get it
- A reference built the OECD way — country, year and a sequence — which CESOP does not accept.
- A UUID of another version, or one with its hyphens stripped.
How to fix it
- Generate a fresh UUID version 4 — for example 3f1a2b4c-5d6e-4f70-8a9b-0c1d2e3f4a5b — rather than composing the value from dates, names or counters.
Check a file for 10050 before you submit
The free validator runs the CESOP business rules against your file and names the error each finding would become — 10050 included — so the Validation Result is not where you first hear about it.
The file is parsed in your browser tab. No upload, no account.
Source: the error catalogue in the Payment Data XSD User Guide — CESOP, v4.40 (DG TAXUD), §2.2.3.18. The explanation is ours; it describes the file format and is not tax advice.