# What evidence does a UK importer keep when it registers for the UK Carbon Border Adjustment Mechanism (CBAM)?

Canonical: https://senseible.earth/answers/uk-cbam-registration-weight-estimate-evidence

HM Revenue and Customs (HMRC) says a registered importer keeps the information it gave at registration with the evidence behind it: the value and dates of imports, when registration was triggered, and how its weight estimates were calculated. This can include information from a third party.

## What HMRC says to keep

- The information provided in the registration process, with any evidence used to support it.
- Records of the value of CBAM goods imported.
- The dates the imports occurred and when they triggered the requirement to register.
- How estimates of the weight of CBAM goods expected to be imported were calculated.
- "any information obtained from a third-party", which the summary says can be included.

## What is estimated

Registration asks for an estimated weight per sector for the coming 12 months, and the importer keeps evidence of how it was estimated. Dates are on the registration page: /answers/uk-cbam-registration-opens-2028.

## What it means for you

Our reading, not HMRC's: a volume forecast you send your buyer may become evidence in its file. Date it, state the period and the basis, such as open orders or last year's tonnes, so the buyer can show where its estimate came from.

## A forecast a buyer can file

- Open orders: 120 t of bar for delivery from January to June 2028.
- Run-rate: 20 t a month, so 20 x 6 = 120 t for July to December 2028.
- Forecast for the 12 months: 120 + 120 = 240 t, sent with the date and the two bases above.

Example tonnes.

## What Senseible does here

Senseible reads fuel invoices and electricity bills into dated records, which feed a plant's emissions figure. It does not forecast UK imports or register importers.

- [When registration opens](https://senseible.earth/answers/uk-cbam-registration-opens-2028)
- [Records your UK buyer will ask for](https://senseible.earth/answers/uk-cbam-importer-records-from-supplier)
- [How the threshold is valued](https://senseible.earth/answers/uk-cbam-threshold-customs-value)

Sources: [HM Revenue and Customs, Carbon Border Adjustment Mechanism (CBAM): Policy summary (updated 2 November 2026)](https://www.gov.uk/government/publications/carbon-border-adjustment-mechanism-cbam-policy-summary/carbon-border-adjustment-mechanism-cbam-policy-summary), [HM Revenue and Customs, Keeping records for Carbon Border Adjustment Mechanism (CBAM) (updated 3 November 2026)](https://www.gov.uk/guidance/keeping-records-for-carbon-border-adjustment-mechanism-cbam)

Last reviewed 2026-11-05. HM Revenue and Customs says the details in its policy summary may be subject to change. Re-check the policy summary and the keeping-records page before relying on a date or condition.