Every international parcel leaving the UK needs a customs declaration, and for Royal Mail that means a CN22 or CN23 form printed alongside the shipping label. The form tells customs what's inside, what it's worth and where it's going, and getting it wrong is the most common cause of international parcels being delayed or returned.
CN22 vs CN23: which form applies
CN22 is the shorter form for lower-value items, typically up to £270, while CN23 is the fuller form for higher-value goods and most parcels containing multiple categories of items. The threshold and which form applies is determined by the item value and destination, and Click & Drop selects the right one automatically based on the details you enter.
The information a customs form needs
A complete declaration needs an accurate description of each item, its quantity, weight, value and the HS tariff code that classifies it. Vague descriptions like 'gift' or 'merchandise' are a common cause of customs delays, so a specific, honest description matters more than sellers expect.
HS codes and why they matter
The HS code is the internationally recognised classification for what you're sending, and customs uses it to determine duties and taxes. You can look codes up online, and while getting one slightly wrong is rarely catastrophic, a missing or wildly incorrect code can hold a parcel up at the border.
IOSS and EORI for EU orders
For orders to the EU under €150, the IOSS scheme lets you collect VAT at checkout and avoid the customer being charged again on delivery. You'll also need an EORI number to export commercially. Our EU customs charge guide explains how these fit together and why they matter.
Printing the form with the label
Click & Drop generates the CN22 or CN23 form as part of the same print job as the shipping label, both in a format that works on a 4x6 thermal printer or standard A4 depending on the service. The form should be attached to the outside of the parcel, usually in a clear documents pouch, so customs can read it without opening the package.
Common mistakes that cause delays
The big three are vague item descriptions, undervaluing goods, and missing or incorrect HS codes. Each can trigger a customs inspection or a charge the customer wasn't expecting, and each is entirely avoidable with a little care at dispatch. It's the same discipline our surcharges guide recommends for domestic post.
Keeping records of declarations
Because customs declarations are legal documents, it's worth keeping a record of what you declared for each shipment, either through your shipping platform's history or a simple export log. If a parcel is queried or a customer disputes a charge, having the declaration to hand resolves it far faster.
Frequently asked questions
What's the difference between CN22 and CN23? CN22 is the shorter form for lower-value items, while CN23 is the fuller form for higher-value goods and multi-item parcels. Click & Drop selects the right one automatically.
Do I need an HS code on a customs form? Yes, each item needs an HS tariff code classifying what it is, and a missing or wrong code can delay a parcel at the border.
Where do I attach the CN22 or CN23 form? Attach it to the outside of the parcel in a clear documents pouch so customs can read it without opening the package.
Customs forms and labels, printed together
Print the CN22/CN23 form and the 100 × 150mm shipping label in one clean pass on a direct thermal printer, ready for the pouch.
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