Post-Brexit Classification: Three Years On, the Errors Are Still Happening

Introduction

The UK's departure from the EU single market required businesses that had never made a standalone customs declaration in their commercial lives to begin making them — accurately, consistently, and at volume — from 1 January 2021. Three years on, classification errors on UK import declarations remain widespread.

Why Classification Errors Proliferate

The UK Global Tariff contains approximately 17,000 commodity codes across 99 chapters of the Harmonised System. Classification decisions made in January 2021 were often reasonable approximations made at speed — and those same codes are still being used in 2026.

What Classification Errors Cost

Misclassification to a higher duty rate results in overpayment, recoverable within the statutory four-year review period. Misclassification to a lower duty rate is the more serious compliance risk — HMRC can raise a C18 post-clearance duty demand for underpaid duties going back three years.

Where Errors Concentrate

From classification audit work across more than 125,000 import declarations, errors cluster in: composite goods, goods that have changed specification, goods affected by post-Brexit tariff schedule restructuring, and goods in chapters with fine technical distinctions (particularly Chapters 84, 85, 39, and 73).

How to Identify Your Exposure

At 99.2% accuracy across all declarations reviewed, MyCustomsInfo®'s classification engine identifies errors that manual review routinely misses.

A MyCustomsInfo® classification audit covers up to 12 months of import declarations and identifies every recoverable and at-risk entry. Book your complimentary assessment. Schedule your assessment.