Importing prefabricated & modular buildings from the UK – customs procedures and documents

Importing prefabricated buildings and modular homes from the United Kingdom to Poland is a topic that combines several complex areas of customs law, building standards and oversized logistics. The UK market offers attractive products: modular homes, portable cabins, office containers, concrete prefabricated elements and even complete steel portal-frame buildings. The value of Polish exports in the HS9406 category (prefabricated buildings) to the UK exceeds USD 56 million per year; however, imports in the reverse direction — from the UK to Poland — are growing alongside demand for fast temporary and modular construction. Before you place an order with a British supplier, you need to know how to classify the goods, what documents are required at the border, how customs inspection of prefabricated buildings works and what duty rates will apply. This article gives you a complete picture of customs procedures when importing prefabricated and modular buildings from the UK — from tariff classification to import VAT.

Tariff classification of prefabricated buildings – HS and CN codes

Correct tariff classification is the foundation of every customs clearance. An incorrect HS code can result in an underpayment of duty (and a subsequent audit) or an overpayment (financial loss).

HS code	Description	Examples
9406.10	Prefabricated buildings of wood	Timber-frame homes, cabins, garden buildings from UK
9406.90	Other prefabricated buildings	Office containers, portable cabins, steel/composite modules
6810	Articles of cement, concrete or artificial stone	Concrete prefabs: panels, beams, staircases
7308	Structures and parts of structures of steel	Steel portal-frame buildings, structural frames — without infill
9406.20	Greenhouses	Polytunnels, prefabricated greenhouses

Key rule: if the product is a complete building supplied in parts for on-site assembly, the correct code will normally be 9406 — not 7308 or 6810. EU customs authorities apply the principle of classification by intended use and condition at the time of import. If you are importing steel profiles alone for self-assembly, this may be 7308; if it is a complete building kit — 9406.90.

Duty rates and the TCA (Trade and Cooperation Agreement)

After Brexit, the United Kingdom and the EU concluded the Trade and Cooperation Agreement (TCA), which from 1 January 2021 allows imports from the UK into the EU (including Poland) duty-free — provided that the rules of origin are met.

Category	MFN rate (without TCA)	TCA rate (with proof of origin)
HS 9406.10 (wood)	3.7%	0%
HS 9406.90 (other)	2.7%	0%
HS 6810 (concrete)	2.0–3.5%	0%
HS 7308 (steel)	0–3.5%	0%

To benefit from the 0% TCA rate, the imported goods must have UK origin status. This means they must be manufactured in the UK or have undergone sufficient processing in the UK. Proof of origin takes the form of: - A Statement on Origin on the invoice or another commercial document — used by exporters registered as UKGE (UK Global Export) or for consignments up to £6,000 - REX (Registered Exporter System) for larger transactions

If the British manufacturer uses materials from third countries (e.g. steel from China), they may not satisfy the rules of origin and the 0% rate will not apply. Always ask the supplier for written confirmation.

Documents required for importing prefabricated buildings from the UK

Customs clearance of prefabricated buildings requires a complete set of documents. A missing document can hold goods at the border or require the lodging of a customs guarantee.

Commercial and transport documents: - Commercial invoice with a description of the goods, value, HS code and parties' details - Packing list — particularly important for oversized shipments - CMR (for road transport) or Bill of Lading (sea) - Statement on Origin (UK) to benefit from the TCA

Technical documents specific to prefabricated buildings: - Declaration of Performance (DoP) — mandatory for construction products covered by a harmonised European standard or a European Technical Assessment (ETA). After Brexit, the UK has its own UKCA (UK Conformity Assessed) system instead of CE. Note: a UKCA certificate is not automatically recognised in the EU and vice versa. For sale in Poland/EU, the product must carry the CE marking or a DoP under the CPR (Construction Products Regulation, Regulation 305/2011). - Assembly/installation instructions in Polish or English - Fire resistance or thermal insulation test certificate — if the product has a defined classification (e.g. EI60 for walls)

Important: If a prefabricated building does not carry the CE marking or a European Technical Assessment, yet falls within the scope of a harmonised standard, placing it on the market in Poland is legally problematic. This should be clarified with the supplier before ordering.

Oversized transport of prefabricated buildings

Building modules, container homes and prefabricated frame sections frequently exceed standard load dimensions. Road transport from the UK to Poland is subject to abnormal-load regulations:

• Standard dimensions: length up to 16.5 m, width up to 2.55 m (or 2.60 m for thermally insulated bodywork), height up to 4.0 m, gross weight up to 40 t
• Oversized loads: require permits in every country of transit and in the destination country. In the UK — a permit from DVSA; in Poland — from GDDKiA. When transiting through Belgium, Germany or the Czech Republic — a separate permit for each country, or a multi-trip permit

VIN / Serial number: Prefabricated buildings and mobile modules (e.g. road-towable cabins on axles) may have a VIN like vehicles. The customs officer may ask for model identification and year of manufacture — prepare technical documentation bearing the serial number.

Customs inspection — what the customs authority checks

When importing prefabricated buildings, the customs authority pays attention to:

1. Customs value — whether the invoice reflects the actual transaction price. Prefabricated buildings have a wide price range (a simple portable cabin from a few thousand pounds, a premium modular home from £80,000 upwards). The officer may cross-reference the customs valuation database.
2. Tariff classification — whether the HS code matches the description. A common error: importing a timber-frame home under "articles of wood" (4418) instead of 9406.10.
3. Origin — documents confirming UK origin for the TCA 0% rate
4. Marking and compliance — especially for construction products covered by the CPR

Uses of prefabricated buildings — temporary vs permanent structures

From a building-regulations and customs perspective, the following distinction is important:

Type	Examples	Customs notes
Temporary (up to 180 days in one location)	Site offices, container offices, seasonal structures	ATA Carnet or Temporary Admission procedures may be used instead of outright import
Permanent / long-term	Leisure lodges, agricultural buildings, modular residential homes	Full import clearance required; CPR/CE required
Mobile (special vehicles)	Road-towable portable cabins on axles	May require vehicle registration — different procedure from buildings

Tip: If you are planning temporary use (e.g. an office container on a construction site for 6 months and then returning to the UK), it is worth considering Temporary Admission rather than full import clearance. This avoids duty and import VAT, provided the goods return to the UK.

Private importers vs companies — import VAT and deductions

Companies (VAT-registered): - On import to Poland, import VAT is payable (23% on the customs value plus duty) - Import VAT can be reclaimed in the VAT return — effectively zero net cost for a VAT-registered business - An EORI number is required to complete customs clearance

Private importers (individuals): - Import VAT of 23% is paid at clearance — no right to reclaim - For goods valued above €150, there is no duty exemption for private individuals - It may be worth considering a purchase through a company even if the prefabricated building is for "private" use (e.g. a leisure lodge) — depending on the tax position