How to complete a CN23 customs form

The CN23 is a customs form used when sending gifts and goods abroad worth more than £270 with Royal Mail.

They are mandatory for all gifts and goods being sent internationally from England, Scotland or Wales anywhere outside the UK, if posting from Northern Ireland they are only needed for posting to non-EU destinations.

Incomplete or absent customs forms are likely to result in items being returned to the sender.

The forms are scanned by optical character recognition, so it is important to fill them in legibly and in BLOCK CAPITALS.

  1. Item description is mandatory – give a detailed description of each article in the item, e.g. “men’s cotton shirts”
  2. Item quantity is mandatory – give the quantity of each item
  3. Item weight is mandatory – enter the weight of each item individually in kg
  4. Total weight is mandatory – enter the total weight of the package including packaging in kg
  5. Item value is mandatory – enter the value of each item going into the package in GBP
  6. Total value is mandatory – enter the total value of the total package in GBP
  7. HS tariff number – is mandatory for businesses only – you need to provide the HS tariff code which you can find at
  8. Country of origin – this is the name of the country where the goods in your package originated, e.g. where they were produced, manufactured or assembled
  9. Postage charge – this is where you can enter how much you’re paying to post your package, including separate charges like insurance
  10. Category of item – select which type of item you’re sending
  11. Comments – you’ve got the opportunity to provide details if your item is subject to quarantine or other restrictions
  12. Add a licence – if your item is accompanied by a licence, tick this box
  13. Add a certificate – if your item has a certificate attached, tick this box
  14. Add an invoice – attach an invoice for all commercial items
  15. Your signature is mandatory – add your signature here
Prefer to fill it out by hand?

Questions and answers

Customs forms are now mandatory if you were sending gifts or goods outside of the UK, except if posting to the EU from Northern Ireland. ​

They allow local customs authorities to make sure the goods are permitted and to calculate if there are any duties or taxes to be paid. Items with missing or incomplete are likely to be returned or delayed.

Currently there are no declaration requirements for goods moved directly between Northern Ireland and the European Union, but customs forms are still needed if posting from Northern Ireland to non-EU destinations.

The latest UK Government guidance on sending parcels to and from Northern Ireland can be found here: ​

All customs forms are available in Post Office branches. If you can’t fill a form in at home, it’s useful to check what information you will need and keep it handy for when you visit the branch.