Shipping from Ireland to the UK: customs fields, HS codes, and the GB gotcha
The four customs fields every parcel from Ireland to Great Britain needs, where they live in Shopify, why carriers expect the country code GB rather than UK, and how to stop retyping all of it.
Short answer
Parcels from Ireland to Great Britain need customs data on the label: an accurate weight, a commodity (HS) code, the country of origin, and a value. In Shopify these fields live on the product's shipping section, so fill them in once per product. One recurring gotcha: carrier APIs, including An Post's, expect the ISO country code GB rather than UK — good shipping software normalises that for you.
The one-paragraph background
Since Brexit, parcels from Ireland to Great Britain are exports and travel with customs declarations. Parcels to Northern Ireland are different — they do not need customs declarations. The rules sit with Revenue and the carriers and can shift, so treat this article as label mechanics, not tax advice: it covers what the label needs so the parcel moves.
The four fields every GB label needs
- Weight — the packed weight of what is in the box, not just the product. An Post rejects a parcel with no weight.
- HS (commodity) code — the classification code customs uses to know what the item is. An Post accepts codes of 6 to 16 characters.
- Country of origin — where the product was made, which is not always where you ship from.
- Value — what the contents are worth, matching what the customer paid.
Where the fields live in Shopify
All of it sits in one place: open the product in Shopify, open the variant, and fill in the Shipping section — weight, HS code, and country of origin. Do it once per product and every future label inherits the right customs data.
If you leave them blank, tools have to guess. EirLink's behaviour is deliberately conservative: a missing weight falls back to the 0.1 kg minimum and a missing HS code falls back to a placeholder — enough to keep a parcel moving, but your own codes are always better. Fill the fields in and forget about them.
The GB vs UK gotcha
Humans write UK; the ISO standard country code — and the code carrier APIs actually accept — is GB. Type UK into the wrong field and some systems reject the parcel outright, usually at the least convenient moment of the day.
This is exactly the kind of detail software should absorb. EirLink normalises UK addresses to GB everywhere they enter the system: the CSV parser, Shopify order imports, and the label payload itself. You never think about it.
Finding HS codes without the headache
You do not need a customs broker for a typical product range. The EU's TARIC database is searchable, and the first six digits of a code are internationally standard. Classify your best sellers once, put the codes on the Shopify products, and the long tail can follow as it sells.
Quick answers
Do parcels from Ireland to Northern Ireland need customs forms?
No — Northern Ireland is treated differently from Great Britain, and parcels there do not need customs declarations. Declarations apply to Great Britain (England, Scotland, Wales).
What happens if a product has no HS code?
EirLink keeps the parcel moving with a placeholder code rather than failing the label, but your own codes are more accurate — and accuracy matters at customs. Add real codes to your Shopify products as soon as you can.
Why do carriers want GB instead of UK?
GB is the ISO 3166 country code, and carrier APIs — including An Post's — validate against it. EirLink converts UK to GB automatically in CSV imports, Shopify orders, and label payloads.
Who pays import charges on a GB order?
It depends on the service and how you sell — charges can be collected from the recipient or handled by the sender's scheme. Confirm the arrangement with your carrier and, for tax questions, with Revenue; this article only covers what the label needs.