If you need to understand how to calculate import duty UK, the process always follows a fixed rule used by HMRC:

Import Duty = Customs Value × Duty Rate

To correctly calculate import duty UK charges, you must first determine three inputs inside the Customs Declaration Service (CDS):

• Commodity code
• Customs value (CIF)
• Duty rate from the UK Global Tariff

In addition, Import VAT is calculated after duty is added, not before. This changes your total landed cost significantly.

Step 1 – How to Calculate Import Duty UK Using the Correct Commodity Code

To calculate import duty UK correctly, you must first identify the correct commodity code.

Commodity codes (HS codes) define your duty rate and compliance rules. Even a small classification mistake can change your import cost.

Use the official UK tariff tool here:
UK Trade Tariff Tool

When selecting a code, consider:

• Material composition
• Product use
• Level of processing

Incorrect classification is one of the most common causes of HMRC reassessments. For example, textiles often carry higher duty rates than electronics, which may be zero rated.

Step 2 – How to Calculate Import Duty UK Using CIF Value

To calculate import duty UK charges, you must calculate CIF value correctly.

CIF = Cost + Insurance + Freight

This is the customs value used in all HMRC calculations.

Example:

CIF value: £5,700

Goods cost: £5,000

Freight: £600

Insurance: £100

Many importers incorrectly use only invoice value, which leads to under-declared customs values. HMRC can adjust CIF if freight documents show higher transport costs.

Step 3 – How to Calculate Import Duty UK Using Duty Rates

Once you have the commodity code, you can apply the duty rate from the UK Global Tariff.

Duty rates vary widely:

• 0% for many raw materials and electronics
• 4% to 8% for general goods
• 8% to 12% for clothing and textiles
• 20% to 30%+ for restricted or sensitive categories

Some goods also benefit from reduced or zero tariffs under Free Trade Agreements such as:

• EU Trade and Cooperation Agreement (TCA)
• Japan UK FTA
• CPTPP agreements

To qualify, you must prove preferential origin with supplier declarations. Without this documentation, HMRC will apply the standard duty rate.

Example calculation:

• Customs Value: £5,700
• Duty Rate: 6%
• Import Duty: £342

Import Duty = 5,700 × 0.06 = £342

This duty is payable before goods are released by CDS.

Step 4 – Calculate Import VAT

Import VAT is often misunderstood because it is not calculated only on goods value.

In the UK, Import VAT is calculated on the total of:

• Customs Value (CIF)
• Import Duty
• Any additional charges (if applicable)

Import VAT formula:

VAT = (CIF + Duty) × 20%

Example using our case:

• CIF: £5,700
• Duty: £342
• VAT Base: £6,042
• VAT (20%): £1,208.40

Import VAT is reclaimable for VAT-registered businesses, but it must still be paid at the point of import or through postponed VAT accounting.

Some goods may also attract excise duty (alcohol, tobacco, fuel), which is added before VAT is calculated. Anti-dumping duties may also apply to certain imports from specific countries, particularly in steel and textile categories.

Step 5 – Submit Your Declaration via CDS

All UK imports must be declared through the Customs Declaration Service (CDS), managed by HMRC.

Your customs declaration includes:

• Commodity code
• Customs value (CIF)
• Country of origin
• Invoice and transport documents
• Duty and VAT calculations

You will also need an EORI number to trade with the UK. Without it, CDS will not accept your declaration.

Once submitted, CDS calculates charges and sends clearance instructions to Border Force. If data matches correctly, goods are released quickly. If inconsistencies appear, HMRC may request supporting documents such as invoices, packing lists, or proof of origin.

Businesses that import frequently often use duty deferment accounts, allowing them to pay customs charges monthly instead of per shipment, improving cash flow.

Worked Example: Full UK Import Duty Calculation

Here is a complete breakdown for a realistic shipment:

Example shipment: Imported furniture components from China

Item	Calculation	Amount
Goods Cost	Supplier Invoice	£5,000
Freight	Shipping Cost	£600
Insurance	Cargo Cover	£100
Customs Value (CIF)	5,000 + 600 + 100	£5,700
Duty Rate	UK Global Tariff (6%)	–
Import Duty	5,700 × 6%	£342
VAT Base	5,700 + 342	£6,042
Import VAT	6,042 × 20%	£1,208.40
Total Import Cost	Duty + VAT + CIF	£7,250.40

This is your true landed cost, not just the supplier invoice value. Many first-time importers underestimate this and face unexpected cash flow pressure when goods arrive at port.

FAQs – How to Calculate Import Duty UK

Do I pay import duty on goods under £135?

Import duty is usually not charged on goods under £135, but Import VAT may still apply depending on the transaction type and seller registration.

How do I find duty rates when learning how to calculate import duty UK?

You can find duty rates using the UK Global Tariff tool by entering your commodity code at UK Trade Tariff Tool. Rates vary by product type and origin.

Can I reduce import duty in the UK?

Yes. You can reduce duty through Free Trade Agreements if you provide valid proof of origin. Some goods also qualify for 0% duty depending on classification.

What is the difference between customs duty and import VAT?

Customs duty is applied to goods based on classification and origin. Import VAT is applied to the total value including goods, freight, and duty.

Conclusion

Understanding how to calculate import duty UK is essential for accurate budgeting and avoiding unexpected landed costs. The process always follows the same structure: determine the commodity code, calculate CIF value, apply the duty rate, and then calculate Import VAT.

Most errors happen at the classification stage or when freight costs are excluded from CIF. Once you apply the correct formula, import costing becomes predictable and easier to manage across suppliers and shipments.

For importers scaling into international sourcing, working with structured clearance support through Custom clearance or import advisory services can reduce errors and speed up CDS processing, especially for high-volume shipments.

A clear duty calculation process gives you control over pricing, margins, and supply chain decisions, which is critical when importing into the UK market.