HS Code — how to find and verify it (ISZTAR-4B + HMRC Trade Tariff)

You can find an HS code in two official search tools: ISZTAR-4B (Poland/EU, 8-digit CN code + 10-digit TARIC) and the HMRC Trade Tariff (UK, 10-digit commodity code). You verify it by comparing the first 6 digits — HS is global, so they must be identical in both systems. If they differ, one of the goods descriptions is wrong and you need to go back to step one. Below is the workflow that in practice saves UK↔PL importers duty surcharges running into thousands of pounds.

HS code, CN, TARIC and commodity code — what they are and how they differ

HS (Harmonized System) is a 6-digit classification developed and maintained by the World Customs Organisation (WCO). Every country in the world uses it — it is the common denominator. Additional digits are a regional layer on top.

The most important practical rule: the first 6 digits (HS) are shared regardless of whether you are looking at CN, TARIC or the UK commodity code. Differences start from digit 7.

How to find an HS code in ISZTAR-4B (Poland) — step-by-step workflow

ISZTAR-4B is the official browser of the EU tariff in Polish, maintained by the Ministry of Finance. You query a single database that integrates TARIC (EU) and domestic Polish measures.

1. Go to ext-isztar4.mf.gov.pl — select the "Nomenclature" tab.
2. Enter the goods description — the more factual, the better. "Men's 100% cotton knitted short-sleeve T-shirt" will work far better than "T-shirt".
3. Navigate the classification tree — chapter (2 digits) → heading (4) → subheading (6 HS) → CN (8) → TARIC (10).
4. Click "Measures" on the target code — you will see: erga omnes duty, preferential rates (including TCA for the UK), domestic VAT, requirements (dual-use licence, CITES, IPAFFS), quotas and anti-dumping measures.
5. Note the date — ISZTAR shows measures "as of today". If your declaration will be filed in two weeks, also check "on a future date", because quotas and anti-dumping rates can change from one day to the next.

For exports from Poland you use 8-digit CN (chapter → heading → subheading → CN). For imports into Poland you use 10-digit TARIC. If ISZTAR shows only 8 digits, click further — the system must generate the two-digit TARIC addition for import consignments.

How to find an HS code in the HMRC Trade Tariff (UK)

The UK left the EU tariff on 1 January 2021 and has since maintained its own — the UK Global Tariff — available at trade-tariff.service.gov.uk. Legal basis: Customs Tariff (Establishment) (EU Exit) Regulations 2020.

1. Open "Find a commodity" on trade-tariff.service.gov.uk — you can search by description or enter the first 6 HS digits from ISZTAR to see what the UK does from digit 7 onwards.
2. Select the heading and drill down until you reach the 10-digit commodity code.
3. The "Import" tab will show: MFN (third-country duty), preferences (including TCA for the EU), standard VAT at 20% or zero/reduced, excise (if applicable) and measures (e.g. VI-1 for wine, CITES, anti-dumping).
4. The "Export" tab will show UK export requirements — strategic licensing, OFSI, sanctions embargo.
5. Check "Valid from / Valid to" — commodity codes have an expiry date. If your goods arrive after the change date, CDS will reject the declaration.

If you need a quick reference for the 20 most common PL→UK export categories, we have a dedicated tool: HS Code UK — easyclearance.pl lookup (table + link to the official HMRC Trade Tariff).

Step-by-step comparison: ISZTAR-4B vs HMRC Trade Tariff

If you operate the UK↔PL corridor, you need to check the code in both systems. Here is a point-by-point comparison of what to look at:

Cross-check: take the first 6 digits from ISZTAR and verify that the HMRC Trade Tariff shows the same chapter description. If it does, the core classification is correct — only the last 4 regional digits remain to be determined. If the descriptions diverge, you most likely have the wrong chapter (e.g. parts vs. finished product).

7 common HS classification mistakes — a verification checklist

Based on our experience handling ~1,200 clearances a year on the UK↔PL corridor and Chinese imports, these are the mistakes that recur most often. Treat this list as a quick QA check before submitting a declaration on CDS or PUESC.

1. 8 digits instead of 10 on import — the client provides CN (8 digits) for an EU or UK import declaration. CDS/AIS will return an error or default to the last digits with a higher duty rate.
2. Code from the supplier's invoice — particularly from China. The manufacturer provided a code for export from China, not for import into the UK/EU. The duty difference can be 6–12%.
3. Parts vs. complete article — an assembly kit can fall under "parts" (the chapter where parts are classified) or under "finished article" under rule 2(a). The General Rules for the Interpretation of HS (GRI) are mandatory — WCO Explanatory Notes are the starting point.
4. Outdated code (previous HS edition) — HS is updated every 5 years; the latest edition is 2022. Codes from a "pre-change" edition go straight to the CDS reject bin.
5. Wrong dominant material — in textiles and furniture, the dominant component by weight governs. "Wooden furniture" that is 51% metal falls under chapter 94 under a different heading.
6. Failure to check measures — the code is correct, but the shipment requires a licence (e.g. dual-use) that the importer does not hold. The goods are stopped at the border.
7. Missing origin declaration — the HS code is correct, but there is no proof of origin (REX, statement on origin), which removes the TCA preference. You pay full MFN instead of 0%. See: Zero-rate TCA duty — UK rules of origin.

How to secure your classification — BTI (UK) and WIT (Poland)

If you are importing the same product on a regular basis, the best investment is a binding tariff ruling. It is issued by the customs authority, is valid for 3 years across the whole EU or the whole UK, and in the event of a dispute it removes the risk from the importer.

BTI — UK (Binding Tariff Information / Advance Tariff Ruling)

• Apply online at gov.uk/guidance/apply-for-a-binding-tariff-information-decision.
• Required: a technical description of the goods, photographs, product data sheet, and a sample (optional).
• Processing time: up to 120 days from acceptance of the application (in practice 2–4 months).
• Validity: 3 years — unless the WCO changes the classification.

WIT — Poland (Wiążąca Informacja Taryfowa — Binding Tariff Information)

• Application via podatki.gov.pl/clo/informacje-o-produktach/wit, submitted electronically through PUESC.
• Fee: free of charge.
• Legal basis: Article 33 of the Union Customs Code (UCC, Regulation 952/2013).
• Validity: 3 years across the whole EU.

For one-off or low-value shipments a BTI/WIT is not cost-effective — it is better to commission a pre-import HS verification from a customs agent or use our reference table in the Check HS Code UK tool.

What happens if you declare the wrong HS code

Three levels of consequences I see in practice:

1. Duty top-up + interest. HMRC and the Polish customs authority conduct retrospective audits — HMRC standard is 3 years, up to 20 years in cases of fraud. Interest accrues on the underpayment (HMRC late payment interest, currently ~7.75% — check the current rate at gov.uk/hmrc-interest-rates).
2. Administrative penalty. UK: the Finance Act 2003 and the Customs and Excise Management Act 1979 provide for financial penalties proportionate to the underdeclaration. Poland: Articles 85 and 87 of the Fiscal Penal Code — up to 720 daily rates.
3. Goods held at the border. For goods subject to measures (licences, anti-dumping), an incorrect code results in an immediate hold at the border. Demurrage costs at Felixstowe / Gdynia / Dover are currently ~£120–£250 per day per container.

HS codes for imports from China into the UK or Poland — what is different

China is the second most common trade corridor I handle after UK↔PL. Classifying a Chinese shipment has three pitfalls that do not arise in EU↔UK trade:

1. The code on the Chinese commercial invoice is a Chinese export HS code — 10 digits, but the last 4 conform to the Chinese tariff, not TARIC or the UK tariff. The first 6 digits (HS) should match, but it is worth verifying each time, because even HS 2022 vs. an older edition can produce a discrepancy.
2. Anti-dumping. Chinese goods are the most common target of EU and UK anti-dumping measures — electric bicycles, bicycles, tyres, ceramics, solar panels, steel. The HS code looks identical to that for goods from Germany, but in ISZTAR/Trade Tariff you will see an additional duty of 30–80%. Always check on TARIC (EU) and the UK Trade Remedies Authority.
3. CE / UKCA certificates. An incorrect HS code can mean you overlook a conformity declaration requirement. An electrical device classified as an "accessory" may slip through the declaration without CE, but at the border Border Force / the Polish customs authority will find the absence of LVD/EMC conformity and the goods will be returned to China at your cost.

The full classification workflow for Chinese shipments is covered in a separate article: Importing from China to the UK via Poland — classification and routing.

FAQ — HS code, verification, CN, TARIC, BTI

What is an HS code and how does it differ from CN and TARIC?

The HS code (Harmonized System) is a 6-digit international goods classification standard developed by the WCO. CN is the EU extension of HS to 8 digits — used on Polish export declarations and Intrastat. TARIC is the extension of CN to 10 digits — required for imports into the EU. In the UK, the equivalent of TARIC is the 10-digit commodity code in the HMRC Trade Tariff.

Where can I find an HS code for exports from Poland to the UK?

For a Polish declaration you use the 8-digit CN code from ISZTAR-4B. For import into the UK your consignee or customs agent uses the 10-digit commodity code from the HMRC Trade Tariff. The first 6 digits must match.

How many digits should an HS code have in a customs declaration?

Export from Poland to third countries — 8-digit CN. Import into Poland/EU — 10-digit TARIC. Import into the UK — 10-digit commodity code. Intra-EU commercial invoice and Intrastat — 8-digit CN.

Can I copy the HS code from the supplier's invoice or a previous shipment?

As a starting point — yes. As a final classification — no. The importer bears the legal responsibility. A Chinese manufacturer's code may be out of date or matched to a different jurisdiction. In practice, around 30% of duty surcharge complaints from my clients start with a code copied from a Chinese invoice.

What is BTI / WIT and when is it worth applying for?

BTI (UK, HMRC) and WIT (Poland, National Revenue Administration) are binding classification rulings — valid for 3 years. Worth applying for when: you are importing the same goods regularly, the product sits on the boundary of two chapters, and the duty rate difference is material. BTI: gov.uk. WIT: podatki.gov.pl.

What are the consequences of an incorrect HS code in a customs declaration?

(1) Duty + VAT top-up + interest (HMRC audits 3 years retrospectively); (2) administrative penalty — in the UK up to 100% of the top-up, in Poland up to 720 daily rates under the Fiscal Penal Code; (3) goods held at the border and demurrage at £120–£250/day. Deliberate under-declaration = criminal liability for the importer/declarant.

Is the HS code the same for export and import?

The first 6 digits — yes, because HS is global. The last 2–4 digits may differ, as each country defines its own regional subheadings. That is why verification requires checking in both systems (country of export + country of import).

Related articles and tools

• HS Code UK — lookup tool (free EC tool: 20 Polish export categories + link to HMRC)
• Commodity code: HS, HS code, CN — classification basics
• UK Global Tariff 2026 — duty rates and changes
• Amazon FBA UK — HS codes and goods classification
• Zero-rate TCA duty — UK↔EU rules of origin
• Duty vs VAT — the difference in UK/PL imports
• CPC — customs procedure code (UK)
• UK export documents checklist
• Importing from China to the UK via Poland — classification and routing
• Duty and VAT on imports from the UK to Poland