Why UK imports get held at the border, and the five things that cause it

A held shipment is rarely a mystery. It is almost always one of five things on the declaration, and four of them are fixable before the goods leave the supplier.

Customs clearance in Great Britain runs through the Customs Declaration Service, or CDS. It is stricter than what came before it: where an older system might have let an inconsistency through, CDS validates fields against each other and rejects the declaration outright. That is not a bad thing — a rejection at submission is far cheaper than a hold at the port — but it does mean sloppy data now stops goods rather than following them.

Here are the five failures, in the order they cost you money.

1. The commodity code is wrong, or nearly right

Commodity codes decide your duty rate, your VAT treatment, and which licences and certificates you need. Get one wrong and you either overpay quietly for years or underpay and face an assessment later, with interest.

"Nearly right" is the expensive version. Codes distinguish between things that look identical on a packing list: the material a fitting is made from, whether a preparation exceeds a sugar threshold, whether a machine is presented with its motor. Two codes that differ in the eighth digit can carry different duty rates and different documentary requirements.

What to do: look every code up in the UK Integrated Online Tariff rather than reusing what the supplier put on the invoice. Suppliers classify for their own export market, not yours. If a code is genuinely ambiguous, apply to HMRC for an Advance Tariff Ruling — it is binding, free, and ends the argument permanently.

2. The EORI number is missing or the wrong one

You need an EORI number to move goods into or out of Great Britain, and for a GB declaration it has to be a GB EORI. An EU EORI will not do, even if the same group company holds one.

This trips up businesses whose freight forwarder has always "handled it". The forwarder declares against your EORI; if it is missing, wrong, or not linked to your CDS access, nothing moves.

What to do: confirm the EORI on file with every forwarder you use, and check it is subscribed to CDS rather than only to the old system.

3. The customs value is built wrong

Duty is charged on the customs value, and the customs value is not simply the invoice total. Depending on the incoterm, it may need to include freight, insurance, royalties, licence fees, or the cost of materials you supplied to the manufacturer free of charge.

Under DDP your supplier has already priced the duty in. Under EXW almost nothing is included and you are adding most of it yourself. Businesses that switch incoterms mid-relationship and keep declaring the value the same way are the ones who get assessed.

What to do: write down which valuation method and which incoterm applies to each supplier, and re-check it whenever terms change.

4. A document code is missing

Many commodity codes require a licence, certificate or waiver, declared as a document code on the entry. Food and feed, plants, animal products, chemicals, dual-use items, and anything with a safety standard behind it will usually need one.

CDS will not guess. If the code demands a document and the declaration does not carry it, the entry fails — and if it fails at the port rather than at submission, the goods sit while you obtain a certificate that can take days.

What to do: when you look up the commodity code, read the measures attached to it at the same time. That is where the document requirements are listed, and it is the step most people skip.

5. The preference claim does not match the code

If you are claiming a reduced or zero tariff under a trade agreement, the preference code on the declaration has to be compatible with the commodity code. If it is not, CDS rejects the declaration.

This is a growing source of error, because more UK trade now moves under agreements with rules to satisfy. Claiming preference is not a box you tick because the goods came from a country you have a deal with — you have to hold proof the goods actually originate there under that agreement's rules, and be able to produce it on audit for years afterwards. We covered how this plays out under the new India agreement in what the UK–India deal actually changes.

What to do: keep origin evidence filed against each product and each supplier, not each shipment. When HMRC asks, they will ask about a product line, and they will ask long after the goods have been sold.

The cash-flow fix nobody sets up early enough

None of the above is about cash flow, but this is: without a duty deferment account, duty and import VAT are due before the goods are released. With one, you make a single payment each month covering everything.

For an importer running weekly containers, that is the difference between paying duty forty times a year at the worst possible moment and paying it twelve times on a known date. It requires approval and usually a guarantee, so it is worth starting before you need it rather than during a squeeze.

What this has to do with your website

More than it looks. Every question above — which codes you work to, which certifications you hold, which incoterms you trade on, which agreements you can supply under — is a question your buyers also ask before they place an order. Most trade businesses answer them dozens of times a week by email and never once on their own website.

Putting those answers on the page does two jobs at once: it shortens your sales cycle, and it makes you findable when a buyer asks a search engine or an AI assistant who can supply what you supply. That is the whole idea behind answer engine optimisation.

If you want a look at what your buyers can and cannot currently find out about you, get AI growth plan.

Sources

• Customs Declaration Service — GOV.UK
• UK Integrated Online Tariff — commodity codes and the measures attached to them
• Customs declaration completion requirements for Great Britain — GOV.UK