The fair value of the Group's trade receivables and other receivables is the same as its book value stated above. No interest is charged on overdue receivables.

At 31 January 2021, trade receivables of £3,541,000 (2020: £3,681,000) were fully performing. Before accepting any new customer, the Group assesses the potential customer’s credit quality and defines credit limits by customer.

The Group applies the IFRS 9 simplified approach to measuring expected credit losses using a lifetime expected credit loss provision for trade receivables and contract assets. To measure expected credit losses on a collective basis, trade receivables and contract assets are grouped based on similar credit risk and aging. The contract assets have similar risk characteristics to the trade receivables for similar types of contracts. The expected credit losses are based on the Group’s historical credit losses which are then adjusted for current and forward-looking information on macroeconomic factors affecting the Group’s customers. The Group has identified gross domestic growth rates, unemployment rates and inflation rates as the key macroeconomic factors in the countries in which the Group operates.

At 31 January 2021, trade receivables of £1,986,000 (2020: £1,262,000) were past due but not impaired. The ageing analysis of these customers is set out below. There has been no change in the credit quality of these balances; they relate to customers where there is no history of default and are still considered fully recoverable.

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The ageing of these receivables is as follows: