From January 1st you will be able to declare two or more low-value parcels into a single import declaration using a reduced data set compared to a standard full import declaration. You may use this process where:

• each postal packet is sent from a country or territory outside the UK to a recipient in Great Britain
• at the time of import, each postal packet contains goods with a relief from import duty available to the recipient of the goods
• the postal packets are imported in such manner as may be specified in a notice published by HMRC
• the total value of each postal packet imported is £135 or less
• the VAT for each postal packet is subject to UK supply VAT, rather than import VAT

For more information please see:

https://www.gov.uk/guidance/apply-to-import-multiple-low-value-parcels-on-one-declaration-from-1-january-2021

You can find the bulk import reduced data set here:

https://www.gov.uk/government/publications/draft-notices-to-be-made-under-the-customs-bulk-customs-declaration-and-miscellaneous-amendments-eu-exit-regulations-2020/bulk-import-reduced-data-set-annex-c