Making an import supplementary declaration


Last updated 22 October 2021

You’ll need to make a supplementary declaration when you import goods using simplified declarations, you must be authorised to use simplified declarations.

When to submit

A supplementary declaration is not needed when your goods are being declared to customs warehousing.

Your supplementary declaration must be sent and accepted by the fourth working day of the month following the month that either:

You can submit your supplementary declaration at any time between the acceptance of your simplified declaration, C21 or when you made the entry in your records and the deadline.

How to submit

You can submit your declaration electronically to HMRC.

Your declaration will need to include:

You also need to provide information like the:

  • consignee and consignor

  • type, amount and packaging of your goods

  • transport methods and costs

  • currencies and valuation methods

  • certificates and licences

Find out the boxes you need to complete on your declaration in CHIEF.

Find out the boxes you need to complete on your declaration in the Customs Declaration Service.

You can submit declarations individually or in batches, and you can submit more than one supplementary declaration for a single simplified declaration.

You can submit less supplementary declarations by combining those with the same header and item level data into a single declaration. This is called aggregation and you must get approval from your authorising customs officer before you do this.

After you submit

When your supplementary declaration is accepted, we will send a customs response message giving a calculation of what you owe. Payment will be taken from your deferment account on the 15th day of the following month.

You’ll also need to submit a final supplementary declaration.

Find out more about what to do if you have missed the deadline for submitting your supplementary declaration.