Accredited official statistics

Overseas trade in goods statistics methodology and quality report

Updated 14 November 2024

1. About HMRC’s Trade in Goods Statistics

HMRC’s Trade in Goods Statistics (TIGS) are a detailed dataset covering the UK’s international trade in goods at a disaggregated country and product level. Using trade declarations, they are published monthly.

These overseas trade statistics provide access to both aggregated and detailed data for over 9,500 commodities and around 200 partner countries.

The Overseas Trade in Goods Statistics (OTS)  were independently reviewed by the Office for Statistics Regulation in October 2010 with publication of the report in February 2011. They comply with the standards of trustworthiness, quality and value in the Code of Practice for Statistics and should be labelled ‘accredited official statistics.’ Accredited official statistics are called National Statistics in the Statistics and Registration Service Act 2007.

HMRC’s TIGS consist of two main accredited official statistics publications:

• Overseas Trade in Goods Statistics (OTS) and its sub-product
• Regional Trade in Goods Statistics (RTS)

This information is accompanied by a range of trade datasets, including:

• exporters and importers details
• goods by preference
• trade and commodity data downloads and
• information on asymmetries

Accompanying detailed data suitable for trend analysis and for comparing the relative magnitude of components is available on UK Trade Info.

Our statistical practice is regulated by the Office for Statistics Regulation (OSR).

OSR sets the standards of trustworthiness, quality and value in the Code of Practice for Statistics that all producers of official statistics should adhere to.

You are welcome to contact us directly with any comments about how we meet these standards by emailing [email protected]

Alternatively, you can contact OSR by emailing [email protected] or via the OSR website.

2. Strengths and limitations

HMRC’s Trade in Goods Statistics is a world leading trade dataset used to identify:

• identify new trade opportunities for products across the world,
• to measure market share
• to identify growth areas
• to forecast trade and
• forecast trade and analyse patterns

TIGS are produced to high professional standards as set out in the UK Statistics Authority (UKSA) Code of Practice for Statistics. An assessment of the statistics took place in October 2010, with publication of the report in February 2011. The full assessment report is available through the UKSA website. A letter confirming National Statistics status of HMRC’s Trade in Goods Statistics is also available on the UKSA website.

Some of the key strengths of this statistical resource are:

• TIGS is a long running statistical series, providing an accurate picture of trade between the UK and the Rest of World originating from administrative data sources. The coverage, timeliness and detail of the dataset is extensive.
• The methodology is continuously revised to ensure coherence and comparability to international standards. This is coupled with strong quality assurance processes and a dedicated team to carry out bespoke credibility checks.
• TIGS has an established reputation, with HMRC’s data being used to inform a wide range of Government policies, a key source for the National Accounts and answer queries from the public.
• HMRC’s data is published to meet the needs of various users, with a dataset that is freely accessible from UK Trade Info for users who wish to explore micro-level data for themselves.

The statistics also have some limitations, including:

• HMRC does not receive nor publish information in respect of trade in services.
• Trade within the countries of the UK, e.g. Great Britain and Northern Ireland, is not included in the dataset. These are considered domestic movements and therefore not international trade.
• Changes to data sources following the UK’s exit from the EU has introduced breaks in the time series, at the beginning of 2021 and 2022. This has reduced comparability across years. More details are in section 3 of this report.

3. Data sources

TIGS are compiled monthly using transaction information collected by HMRC; and includes commodity codes to classify the types of goods being traded. Learn more about how goods are classified.

3.1 UK to EU exports

Up to 31 December 2020, UK to EU export statistics were collected via Intrastat. This required traders to declare the value and volume of commodities exported to EU Member States within the relevant month of physical goods movement.

For goods moving from 1 January 2021, GB to EU export statistics were compiled from customs export declarations made according to the requirements of the Taxation (Cross Border Trade) Act. The customs declaration requirements are more complex than the single monthly aggregated Intrastat return and can result in differences between dates of declaration and actual movement of the goods.

The TIGS methodology relies upon the clearance date of the customs export declaration for its inclusion within the relevant month of account rather than the declared physical movement date used from the Intrastat survey.

Intrastat survey returns continue to be collected for goods exported from Northern Ireland to EU Member States, under the terms of the Northern Ireland Protocol.

The UK to EU export dataset combines the GB to EU customs export declaration data and NI Intrastat export (dispatch) data.

As a result of the changes and differences outlined above, there was a break in the timeseries for published UK to EU export statistics from January 2021. Caution should be used when comparing data collected using Intrastat with Customs Declarations (please see section 3.4).

3.2 UK imports from EU

Up to 31 December 2021, UK from EU import statistics were collected via Intrastat. This required traders to declare the value and volume of commodities imported from EU Member States within the relevant month of physical goods movement.

Unlike exports, UK imports from EU statistics were not affected by any change in 2021. The Intrastat survey continued to operate for all UK (GB and NI) imports (arrivals) from EU Member States. This mitigated the effects of staged customs controls, a policy allowing the delay of submission of customs declarations to support traders to support importers during 2021 (see Annex E) and allowed compliance with the Northern Ireland Protocol.

However, from 1 January 2022, Intrastat only became applicable for movements of goods between NI and the EU. Statistics on imports to GB from the EU were compiled from customs import declarations.

The TIGS methodology relies upon the clearance date of the customs import declaration for its inclusion within the relevant month of account rather than the declared physical movement date used from the Intrastat survey.

The UK imports from EU dataset combines the GB from EU customs import declaration data and NI Intrastat import (arrivals) data.

As a result of the changes and differences outlined above, there was a break in the timeseries for published EU to UK import statistics from January 2022. Caution should be used when comparing data collected using Intrastat with Customs Declarations (please see section 3.4).

3.3 UK trade with Non-EU countries

The data source for UK Trade with Non-EU countries is Customs Declarations and did not change following EU exit.

Non-EU trade statistics are compiled from two systems: CHIEF (Customs Handling of Import and Export Freight) and the Customs Declarations Service (CDS).

3.4 Comparing Intrastat returns with customs declarations

There are significant differences between how data is collected from the Intrastat survey and from the administrative customs declarations. This means data previously collected from Intrastat are not strictly comparable with data currently collected from customs declarations. The main features of the two collection methods are outlined below.

a) Intrastat

• Intrastat is a monthly survey, requiring returns from those importing and exporting with EU Member States above set value thresholds. Before EU Exit, returns were required from all UK businesses (registered for VAT) who imported at least £1.5 million and/or those who exported more than £250,000 by value per annum.
• Traders declare goods that physically moved in a calendar month, by 21st of the following month.
• Trade below the value threshold is estimated using the Below Threshold Trade Allocations (BTTA) methodology (section 5.4). These thresholds are derived using the value declared on VAT returns (Boxes 8 & 9).
• The value of trade not submitted on-time is estimated. If a trader submits at a later date, then the non-response estimate is corrected or removed.
• Transactions (that is, invoice lines) with a value of £175 or less can be aggregated and classified to a single commodity code (99500000) (See section 8.3).

b) Customs declarations

• Customs import and export declarations are required to process the movement of goods at the border. In addition, certain data variables are used to compile the trade statistics, and so considered an administrative data source.
• The acceptance/clearance date on the export declaration and the received/cleared date on the import declaration, determine the month of trade. This date can be different from the actual physical movement of goods took place.
• The use of administrative data does not require estimation outside quality assurance process.
• Individual declarations with value of £873 and 1,000kg or less (other than parcel post) are aggregated under a single CN commodity code (99500000) (See section 8.3).

4. Relevance

Trade in Goods Statistics are compiled to serve the needs of many users, including governments, business community, compilers of other economic statistics such as balance of payments and national accounts, various regional and international organisations, researchers and the public.

They are used to identify new trade opportunities for products across the world, to measure market share, to identify growth areas, to forecast trade and to analyse patterns. Different users need different data, ranging from detailed to aggregated figures.

One of the key uses of the OTS is as a component to the UK’s Balance of Payments (BoP). The Office for National Statistics (ONS) adjusts the OTS to produce trade in goods data on a BoP basis. Trade in Goods Statistics are regarded as an important indicator of the economic performance of the UK. Export data, in particular, is used for example as an indicator of the state of health of the UK manufacturing industry.

The statistics are also used to answer press queries, parliamentary questions and Freedom of Information requests. Other Government Departments rely on HMRC’s data to inform evidence-based policies.

To enable users to customise their analyses, HMRC publishes detailed TIGS datasets, as well as interactive tables, available on UK Trade Info.

5. Accuracy and Reliability

HMRC carries out extensive validation procedures as part of its data processing. These activities ensure the accuracy and reliability of the TIGS dataset.

5.1 Validation

A validity error is where a data field has been submitted in an incorrect format or is missing required data. Validity checks are carried out in three ways:

• electronically by HMRC’s systems
• verifying data fields by reference to the original source document or
• by contacting the business or agent

Autocorrections are built into HMRC’s computer systems to cope with certain common types of error including:

• obsolete or partially invalid commodity / port codes
• missing quantities and
• inconsistencies between port and mode of transport

5.2 Credibility checks

A credibility ‘risk’ is where data has been submitted to HMRC in such a way that there is a high probability that it is incorrect. For example, a value or weight combination that is implausible for the product.

HMRC has developed parameters for each commodity code. These provide estimates of credible relationship between value and quantity. This then identifies outliers for further investigation.

Targeted interventions take place with businesses submitting Intrastat and customs declarations. These interventions provide a valuable quality assurance tool:

• identifying and correcting errors and omissions that have occurred before publishing the TIGS datasets and
• improving the likelihood that future declarations will be of good quality and declared on time

5.3 Asymmetries in trade data

Asymmetries are a tool to compare statistics between countries and assess data quality. They consist of differences between a country’s published trade statistics and those of its trading partners.

For example, there may be a difference between what the UK records as imports from France, and what France records as exports to the UK. Ideally, these figures should match. The United Nations’ Concepts and Definitions for International Merchandise Trade Statistics (IMTS) contains recommendations to try and minimise any differences.

HMRC monitors these discrepancies on a regular basis. Further information on trade asymmetries are available from GOV.UK.

5.4 Estimation

Estimation only relates to data received via Intrastat, as this is a survey carried out on a subset of traders and subject to non-response. From January 2022 , this only applied to goods movements between Northern Ireland and EU Member States.

a) Below Threshold Trade Allocations

Intrastat only collects detailed returns from traders above the Intrastat threshold. HMRC estimates the value of trade from business below the threshold, known as Below Threshold Trade Allocations. Details from VAT returns are used to do this.

• Step 1: summing the values of arrivals (Imports from EU to Northern Ireland) and dispatches (exports from Northern Ireland to the EU)

• Step 2: estimating the total value, net mass and supplementary units for each combination of Combine Nomenclature (CN) 2-digit product chapter and partner country

The estimates are based upon the levels of trade in products and by partner countries conducted by those businesses who are just above the Intrastat threshold.

b) Ancillary Cost Survey

The monthly Ancillary Costs Survey (ACS) allows HMRC to publish Northern Ireland to European Union trade figures on the same common valuation basis as all the other EU Member States.

This basis is the value of the goods plus the cost of movement to the border of the Member State that publishes the statistics, i.e. the Cost, Insurance and Freight (CIF) delivery terms value for arrivals and the Free on Board (FOB) delivery terms value for dispatches. The value of the trade under this common basis is called the statistical value.

c) Non-response and partial response estimates

Non-response and partial response estimates for missing returns are included by HMRC:

• when businesses fail to provide Intrastat returns by the required deadline or
• when the value of the return is substantially lower than expected (so a further declaration is likely)

This is to ensure the provisional monthly publication of total trade figures is as accurate as possible, taking account of declarations that will be submitted late.

The expected trade by each business is based on the declarations made by that business in previous periods. When traders do submit a declaration, but the value is substantially lower than expected, a certain amount of the shortfall is retained as a partial response estimate. This partial response estimate is calculated using a similar method to the non-response estimate.

d) Trade associated with Missing Trader Intra Community (MTIC) VAT fraud

MTIC VAT fraud is a systematic criminal attack on the VAT system which has been detected in many EU Member States. In essence, businesses get a VAT registration to acquire goods VAT free from other Member States. They then sell on the goods at VAT inclusive prices and disappear without paying over the VAT paid by their customers to the tax authorities.

The MTIC-related trade adjustments were added to the EU arrivals estimates derived from operational and intelligence information, as it is this part of the trading chain that is not recorded. These adjustments did not reflect the level of trade associated with this fraud and were not a proxy to estimate the level of attempted fraud or the VAT loss. Instead, they were simply an estimate of the missing EU arrival trade not recorded as a result of the fraudulent activity.

The method used for calculating the adjustments relied on information uncovered during Customs’ operational activity. As such, it cannot be detailed for risk of prejudicing current activity and undermining the ability to tackle the fraud effectively.

From January 2022 account, MTIC estimates were removed from the Overseas Trade in Goods Statistics. There were two main drivers for this:

• the implementation of full customs controls for all EU imports coming into GB, following the ending of staged customs controls and
• MTIC and VAT Supply Chain Fraud have evolved, the complexities of their operation are not purely EU-centric.

As a result, it is no longer appropriate to estimate mis-declaration by comparing exports and imports in supply chains.

e) Net mass estimation

From January 2010, HMRC estimates for missing net mass declarations in all EU commodity codes where this is a voluntary data element, in compliance with EU legislation. Where a declaration is received with:

• a zero
• blank or
• invalid net mass

an estimated net mass, derived from the commodity code’s factor and the declared supplementary unit, is calculated and inserted into the net mass field.

This series of factors is created annually by Eurostat, and provides a consistent standard across the EU.

f) Specific movements

There are various ‘Specific Movements’ and other specific cases which, by the very nature of the goods or the types of trade involved, are not captured by customs declarations or via Intrastat. As a result, different procedures are adopted by HMRC to include such trade in the statistics.

More detail is provided in Annex B.

6. Timeliness and Punctuality

TIGS datasets are released on a monthly basis. Figures are published within 6-8 weeks of the end of the reporting period. This allows time to compile, quality assure and produce the statistics while ensuring they are timely for users.

Under the Code of Practice for Statistics, the release calendar for the Overseas Trade in Goods Statistics publications is announced twelve months in advance of the actual release.

The release calendar is available on GOV.UK and UK Trade Info.

7. Accessibility and Clarity

TIGS datasets are freely accessible on the UK Trade Info website, following Government Digital Service (GDS) guidance. An accessibility statement is available on HMRC’s UK Trade Info.

HMRC’s website is partially compliant with Web Content Analytical Guidelines 2.1 AA standard accessibility requirements. The AA standard has been adopted by the government and written into the Public Sector Bodies (Websites and Mobile Applications) Accessibility Regulations 2018.

The TIGS datasets are aggregated data available in pre-defined fixed tables whilst detailed commodity code level data is available from the interactive tables and bulk datasets. Alongside these datasets, we also release commentary reports. The commentaries detail the UK’s major commodity types traded and trade partners.

Users of trade data statistics can also access international data and publications at:

• the COMEXT database provided by Eurostat, the statistical office of the European Union
• Eurostat international trade in goods publications
• the United Nations’ Commodity Based Trade Database (ComTrade)

8. Coherence and comparability

HMRC’s Trade in Goods Statistics are compiled in line with the United Nations recommended methodological guidelines on International Merchandise Trade Statistics (IMTS). The datasets allow for comparison over time and regions, using harmonised methods.

8.1 System of recording trade statistics

There are two recognised systems for recording trade:

• general trade
• special trade

The key difference between the two is the treatment of goods entering Customs warehouses and free zones / freeports. Special trade excludes such movements.

HMRC and the ONS applied the general trade system (as described in UN’s IMTS) to compile UK trade statistics up to and including the April 2016 month of account.

Following a change in legislation on 1st May 2016, affecting the way in which goods are declared to Customs, HMRC’s TIGS datasets switched to the special trade system.

This means goods imported into customs warehouses and free zones / freeports are only recorded once they enter:

• free circulation or
• certain customs procedures (e.g. Inward Processing)

Re-exports from customs warehouses and free zones are not recorded under the special trade system. Goods in transit through the UK (even where transhipment is involved) are not included in the TIGS dataset.

8.2 Basis of valuation

For statistical purposes the UK adopts the valuation basis recommended in the UN’s methodological guidelines on IMTS. This is termed the statistical value.

The valuation of exports is on a Free on Board (FOB) delivery terms basis. This includes the value of the goods, and all the costs involved (such as freight and insurance) in transporting them from the supplier to the point of final dispatch from the UK.

The valuation of imports is on a Cost, Insurance and Freight (CIF) delivery terms basis. This includes:

• the cost of the goods
• charges for freight and insurance and
• all other related expenses in moving the goods to the point of entry into the UK (but excluding any duty or tax chargeable in the UK)

When goods are re-imported after processing abroad, the valuation includes the value of the goods when exported as well as the cost of the processing.

a) Value of trade collected from Intrastat

The value of trade collected through Intrastat declarations is the invoice value. This is consistent with that required for VAT accounting purposes. HMRC conduct sample surveys to establish conversion factors to adjust the invoice values. This allows the production of the legally required valuation basis (i.e. statistical value). Separate factors are imputed for a range of different delivery terms and for trade with each Member State (see Ancillary Costs Survey - section 5.4b).

b) Value of trade collected from customs declarations

The statistical value of imports and exports is the same as the value for customs purposes. When submitting customs declarations, businesses declare the statistical value, using specific methods of valuation in the following order of preference:

• the transaction value of the goods (i.e. the price paid or payable on the goods)
• the transaction value of identical goods
• the customs value of similar goods
• the ‘deductive method’ - value derived from the selling price in the country of importation
• computed value based on the built-up cost of the imported goods and
• the ‘fall-back’ method by adopting the above methods flexibly to fit unusual circumstances

Goods are valued at the point where they enter into or leave the UK. This means that costs for delivery of imported goods to that point have to be included in the customs value.

Amounts expressed in foreign currency are converted to sterling by the importer using a system of ‘period rates of exchange’ published by HMRC. These rates are normally operative for a four weekly period unless there is a significant movement in the exchange rate.

c) Treatment of taxes

The value of all goods moving into and out of the UK is based on the statistical value. In line with this principle the values recorded exclude VAT, as are all other taxes such as duties and levies applied to goods after arrival in the UK.

Data received via Intrastat captures the value of the goods based on the declared invoice or contract amount. This also excludes VAT and excise duties from the value recorded for trade.

Publication of VAT and Customs and Excise duties does not form part of the TIGS dataset.

8.3 Low value consignments

For trade in goods collected from customs declarations (UK trade with Non-EU and GB trade with EU), imports and exports of an individual value of £873 or less are automatically aggregated as part of the statistical production process, into SITC group 931 – ‘Special transactions and commodities not classified according to kind’, and classified to a single commodity code (99500000). This trade is not analysed either by commodity or country. Statistics for individual commodities are thus deficient by these amounts.

For Intrastat (Northern Ireland trade with the EU), transactions with an invoice value of £175 or less, can be aggregated and classified to a single commodity code (99500000). This process is a facilitation that the trader / declarant can undertake if they so choose. Intrastat declarations of less than £175 are not automatically aggregated as part of the statistical production process.

As customs declarations and Intrastat treat low value consignments differently, the two sources are not strictly comparable. In particular, it is not possible to compare combinations of countries and commodities before and after EU Exit. Due to the automatic aggregation of low value customs declarations, this will remove the details of many ‘low volume’ commodity / partner country combinations in the published OTS.

Consequently, the change in data source from Intrastat to customs declarations for GB trade with the EU (from January 2021 for exports, and January 2022 for imports) will impact and lower the total number of these commodity / partner country combinations present in the OTS.

8.4 Comparability with trade in goods statistics published by the Office for National Statistics (ONS)

The ONS and HMRC report trade data on a different basis, and this can cause differences between the value of trade reported by the two organisations.

HMRC records each transaction involving goods leaving or arriving in the UK customs territory as trade. This collection methodology is defined in the United Nations Manual of International Merchandise Trade Statistics (IMTS 2010).

The ONS publishes trade statistics on a Balance of Payments basis as per the International Monetary Fund (IMF) 6th edition of the Balance of Payments and International Investment Position Manual (BPM6). This recording of trade is necessary for the compilation of Gross Domestic Product (GDP) figures by the ONS, and it uses a slightly different definition of goods trade.

In particular, the BPM6 method is based on principles of residence and change of ownership. The ONS compiles its goods trade statistics starting from HMRC data and then makes the necessary adjustments to have the goods flows conform to the Balance of Payments methodology.

One of the main differences between ONS and HMRC data is how trade flows not involving ownership changes are treated.

If a good arrives in the UK for maintenance or processing without any change in ownership, this will be recorded as goods trade by HMRC (IMTS basis) but not by the ONS (BPM6 basis). A good that changes ownership but never leaves the British soil can be recorded as trade by the ONS but it is generally not recorded by HMRC.

ONS measures trade through both exports and imports of goods and services. Data are supplied by over 30 sources, including several administrative sources, with HMRC being the main source for trade in goods.

8.5 Geographical comparisons

Regional Trade in Goods Statistics (RTS) provide a useful breakdown of the imports and exports of the UK regions consisting of:

• 9 English regions
• 3 Devolved Administrations (Scotland, Northern Ireland and Wales)

and its international partner countries. Regional statistics at a lower-level geography are available in linked publications. The TIGS dataset is the basis for this, so the same methodologies apply. The geographical nomenclature used in RTS is the International Territorial Level 1 (ITL1).

The RTS methodology allocates trade in goods based on the proportion of a business’ employees in a region instead of allocating trade entirely to a region where a business’ head office is located. This is carried out using the ONS Inter-Department Business Register (IDBR).

9. Suppressions

Suppressions are used to conceal potentially disclosive information from the public domain.

Disclosive data is any data that could:

• reveal the commercial activities of a business or
• if published, be against the national interest

In some situations, it may be necessary to withhold the publication of such statistics. This disclosive data may then be aggregated to a higher level of detail so that such inferences cannot be made.

There are two main types of confidentiality system used in Official Statistics:

• Active confidentiality involves evaluating all data. Data that may reveal the commercial activities of an individual business would be automatically suppressed. This is the standard for Official Statistics.
• Under passive confidentiality, data is only suppressed if a request for suppression is granted. So, under passive confidentiality it is perfectly acceptable to publish disclosive data. If a suppression has not been requested data will be published irrespective of whether it reveals commercial activity or not.

When publishing the TIGS dataset, HMRC follows a system of passive confidentiality.

Requests for suppressions from a business or government department will go through an evaluation process. If appropriate thresholds are met the suppression(s) will applied at 8-digit commodity code level as required by legislation. Due to this rule, TIGS is exempt from the active confidentiality normally applied under the UK Statistics Authority’s (UKSA) CoP for Official Statistics.

Further detailed information can is available in HMRC’s published Suppression Policy.

10. Revisions

Provisional estimates of statistical data are regularly revised and updated to provide more complete information when it becomes available.

There are two types of revisions that can be used with the OTS. These are ‘scheduled revisions to provisional data’ and ‘unscheduled corrections to final data’. Through such a process, published statistics can become more accurate.

Further detailed information can be obtained from HMRC’s published Revisions Policy. For actual revision reports / data sets please see the OTS Revisions.

11. Annexes

The following set of annexes accompany this report:

• product and territorial classifications
• specific cases
• other specific cases
• trade data by preference
• collection and methodology changes following the UK leaving the EU