How to Pack for International Shipping from the UK

Sending a parcel abroad involves a few extra steps compared to posting within the UK, and getting them wrong tends to mean delays, returned parcels, or unexpected charges landing on the recipient rather than anything that affects you directly until the complaint arrives. None of it is complicated once you know what's required, but it's worth getting right from the first international order rather than learning the hard way.

This guide covers what's different about packing for international shipping from the UK, the customs paperwork you'll need, and how to pack so your parcel survives a longer and less predictable journey than a domestic one.

What's different about international parcels

Beyond the postage cost itself, three things separate an international parcel from a domestic one: customs declarations are required, transit times and handling are generally less predictable, and the parcel often passes through more handling points and a wider range of conditions than a domestic journey. Packaging that's adequate for a same-day UK courier route isn't automatically adequate for a parcel that might spend several days in transit and pass through multiple sorting and customs facilities.

Customs declarations: what you actually need

Any parcel containing goods or gifts sent from the UK to another country requires a customs declaration. This applies regardless of whether you're a registered business or an individual sending something through a marketplace platform.

From 1 June 2026, Royal Mail and Parcelforce require a CN23 customs declaration for all postal international shipments, replacing the previous system where lower-value parcels used a simpler CN22 form. The CN22 is no longer used or available for selection except in specific combined label scenarios. This is a recent change, so if you've shipped internationally before and are used to the older CN22 process for smaller parcels, it's worth knowing the requirement has moved to CN23 across the board for Royal Mail and Parcelforce postal services.

The easiest way to complete this is through Royal Mail's Click and Drop service, which generates a compliant customs declaration and address label together, removing the need to fill in a paper form by hand. If you're dropping a parcel at a Post Office counter without having prepared this in advance, you can complete the customs declaration online beforehand and bring the reference number or QR code with you, which speeds up the process considerably compared to filling in a form on the spot.

For couriers other than Royal Mail, such as DPD, DHL or UPS, the customs declaration process is generally handled through their own online shipping tools rather than a CN23 form specifically, though the underlying information required, contents, value, country of origin, HS code, is broadly similar.

What information you need ready

Before starting a customs declaration, have the following to hand for each item in the parcel: a clear, specific description of the contents (vague descriptions like "gift" or "goods" are not sufficient and can cause delays), the quantity of each item, the value of each item, the country where the goods were manufactured or originated, and where required, a commodity code (HS code) for what you're sending. For C2C senders, if the country of origin for a gift isn't known, this can generally be entered as GB, but for business sellers, accurate origin information is expected.

Being vague or inaccurate on a customs declaration isn't just a compliance issue, it's also the most common reason international parcels get held, delayed, or returned to sender. A specific, honest description that's quick for a customs officer to understand and act on moves through the process far more smoothly than something generic.

Attaching the customs form correctly

The customs declaration needs to be securely attached to the outside of the parcel, ideally on the same side as the address label so everything relevant is visible together. If there isn't enough space, it can go on the back of the item instead. A CN23 form should be placed inside a clear plastic wallet before being attached to the parcel, which is available at the Post Office, to protect it from damage or smudging during handling. A form that's damaged, illegible or comes loose during transit causes the same kind of delay as one that was never attached properly in the first place.

Packing for a longer, less predictable journey

International parcels typically experience more handling points than domestic ones: collection, outbound sorting, international transit, customs processing in the destination country, and then onward distribution through that country's postal or courier network. Each additional point is a chance for rough handling, so packaging that's adequate for a quick domestic hop deserves an extra look before it's sent further afield.

Clothing and soft goods

A standard mailing bag is still the right choice for clothing being sent internationally, but it's worth checking the seal is pressed down with extra care given the longer journey and additional handling points involved. Our mailing bags in 50 to 60 micron LDPE handle the extra transit time well, provided the seal is fully engaged along its entire length rather than just the centre section.

Small items and jewellery

For small items being sent internationally, the case for containing them properly before they go into outer packaging is even stronger than for domestic parcels, given the additional handling involved. A small grip seal bag keeps the item contained, organised, and protected from movement across a journey that may involve several more touchpoints than a same-day domestic delivery. Browse our grip seal bags for sizing suited to jewellery, small accessories and samples.

Sealing properly for the journey ahead

Whatever you're sending, the seal or seam holding the parcel together needs to withstand more handling than a domestic equivalent. For boxed items, the H-tape method, one strip along the centre join and one down each side seam, both extending onto the box wall, gives a meaningfully more secure seal than a single central strip, and this matters more for international transit than for a quick domestic journey. Our packaging tape range covers the width and adhesive types suited to both lighter parcels and heavier boxed shipments.

Weight and size matter even more for international postage

International postage pricing is generally more sensitive to weight and dimensions than domestic pricing, since rates typically scale by weight band and by zone. An oversized box or an unnecessarily bulky outer bag doesn't just look untidy; it can meaningfully increase the cost of an international shipment compared to a correctly sized one. This makes getting the right size of mailing bag or box more financially relevant for international orders than it might be for a domestic parcel where the price difference between size brackets is often smaller.

Restricted and prohibited items

Different countries have different restrictions on what can be imported, and these vary considerably. Items that are perfectly fine to send within the UK, certain cosmetics, foods, electronics with batteries, anything with a liquid or aerosol component, may be restricted or require specific documentation for some destination countries. It's worth checking the specific restrictions for your destination country before dispatching anything outside the obvious categories of clothing, books and general goods, since this responsibility sits with the sender regardless of whether the platform you're selling through flags it for you.

Who pays customs duties and taxes?

This is worth being clear about before you ship internationally, since it affects buyer expectations. Depending on the destination country and the value of the goods, the recipient may be liable for import duties, VAT, or handling fees charged by the courier or postal service on arrival. This is generally separate from the postage cost you've paid as the sender, and it's worth making clear to buyers, particularly if you're shipping internationally as a regular part of your business, so they're not caught out by an unexpected charge when the parcel arrives.

A practical checklist for international parcels

Before sending anything abroad from the UK: confirm what destination country restrictions apply to what you're sending, complete the customs declaration with specific, accurate descriptions and values for every item, attach the form securely to the outside of the parcel in a protective wallet where applicable, choose packaging appropriate to a longer and less predictable journey, with extra care on sealing, and check the size and weight of your parcel against the postage pricing bands, since correctly sized packaging makes a bigger difference to cost on international shipments than domestic ones.

You can browse our full range of mailing bags, grip seal bags and packaging tape to make sure your international parcels are packed to handle the extra distance and handling involved.