What is an MRN Number in UK Customs? Complete Guide 2026

If you’ve ever shipped goods between the UK and EU, you’ve likely encountered an MRN — Movement Reference Number. It’s one of the most important reference codes in the UK customs system. Here’s everything you need to know.

What is an MRN?

An MRN (Movement Reference Number) is a unique identifier assigned to every customs declaration submitted to HMRC through the Customs Declaration Service (CDS). It confirms that a declaration has been registered and is being processed. The format is: YYGBXXXXXXXXXXXXXXXXX — two digits for the year, followed by “GB” and a long alphanumeric string.

When Do You Get an MRN?

An MRN is generated at the moment a customs declaration is submitted:

• Export MRN — issued when your customs agent submits the export declaration in HMRC CDS before goods leave the UK
• Import MRN — issued when the import declaration is submitted in Poland’s PUESC system (or another EU country’s customs system)
• Transit MRN — issued when a T1 transit procedure is opened in NCTS

MRN vs. GMR — What’s the Difference?

These two numbers are often confused:

• MRN — identifies the customs declaration (what goods you’re moving)
• GMR (Goods Movement Reference) — identifies the vehicle and ferry booking in the GVMS system. The driver needs the GMR to board at Dover, Folkestone, or Holyhead

Both numbers are generated by your customs agent before the truck departs. A good agent sends both via WhatsApp or email in minutes.

How to Track Your Shipment Using MRN

You can check the status of your customs declaration using the MRN in:

• HMRC’s CDS portal (for UK export declarations)
• Poland’s PUESC e-Klient system (for import declarations)

Status “Released” means the goods can be physically collected from the customs-controlled area. Easyclearance.pl provides real-time status updates and forwards MRN numbers directly to your driver and logistics team.