The scope pages from HM Revenue and Customs (HMRC) for the United Kingdom (UK) Carbon Border Adjustment Mechanism (CBAM) talk about 10-digit codes but the return needs 8 digits. Which does our buyer use?

The return and the records use the 8-digit commodity code in force when the goods pass the tax point. HMRC explains codes up to 10 digits on its scope pages, and prints its lists at 2, 4, 6 or 8 digits. We found no line asking for 10 digits.

What HMRC says about the number of digits

• Records page: each CBAM good needs its "8-digit commodity code and description".
• Policy summary: the return lists goods "by reference to the relevant 8-digit commodity code in force when the good passed the tax point".
• Sector scope pages: a code ends as a "final 10-digit code (also known as a Combined Nomenclature (CN) code)", for example 2523 2900 00.
• Policy summary annex: the headings say "Combined Nomenclature (CN) code", but the codes are printed at 2, 4, 6 or 8 digits, for example 7601, 7303 00 and 2523 10 00.

Why it looks like a mismatch

A commodity code is like a postcode. The first digits narrow it to an area and the extra digits narrow it to a street. Our reading: HMRC calls both the 10-digit and the shorter codes by the same name, CN code, which is why this is confusing.

The list can stop at 4 digits, for example 7601, and still cover everything under it. The return needs the 8-digit code of the actual good.

Our reading, not HMRC's

The first 8 digits of a 10-digit code are the part the return needs. HMRC does not say so in these pages, so confirm it with your buyer's customs broker before relying on it.

What to do on your invoices

• Ask your buyer for the 8-digit code it will put on its return.
• Write that code on the commercial invoice next to your own code.
• Use the same code on the packing list and shipping papers.
• A buyer's records must show the code, so a mismatch between papers can slow its filing.

What Senseible does here

Senseible reads fuel invoices and electricity bills into dated, fingerprinted records. It does not set commodity codes or tell you whether a product is in the UK CBAM. Your buyer's customs broker, or HMRC, settles that.

• Which listed code covers my code
• What each shipment line needs
• Which customs documents count as records
• UK CBAM for Indian exporters

Sources: HMRC, Keeping records for CBAM (updated 3 November 2026), HMRC, Carbon Border Adjustment Mechanism (CBAM): Policy summary (updated 2 November 2026), HMRC, Check which goods are in scope of CBAM (sector pages, updated 16 July 2026)

Last reviewed 2026-11-07. Digit lengths are from HMRC's records page (updated 3 November 2026), policy summary (updated 2 November 2026) and sector scope pages (updated 16 July 2026). The reading about the first 8 digits is ours. Re-check when HMRC updates the scope pages.