It’s a common issue and area of confusion and it has tax implications. WIP is valued at the lower of cost or net realisable value but Debtors whether invoiced or not are valued at Sales Value, uninvoiced Sales are shown as Amounts Recoverable on Contracts within Debtors.
Here is an example from HMRC
A joiner contracts to create fitted bookcases in an office for a total price of £15,000. He purchases the timber (materials cost £6,000) and builds the doors in his workshop. He also prepares the timber for the rest of the structure in his workshop. He then builds the skeleton of the bookcases on the customer’s premises and attaches thereto the timber that he has already prepared in his workshop. What is the accounts treatment if his year end occurs after he has prepared the timber and the doors but before he has gone to the customer’s premises to build the skeleton and fit them?
The contract is a single contract and the joiner should recognise revenue according to the stage of completion of the work. It is not relevant whether the work is done at his workshop or at the client’s premises. Neither is it relevant that part of the contract can be regarded as ‘goods’ and part as ‘services’: both are treated in the same way for accounting purposes.
Let us assume the joiner assesses that he has done 1/3 of the work by the year end and he has used half of the timber and other materials. The calculation would be: total price £15,000 less materials at cost (£6,000) leaves £9,000. Assuming the profit attaches only to the labour, accrued income is £3,000 (1/3 complete) plus materials at cost of £3,000 ( a half used), a total of £6,000. The remaining half of the total cost of the materials (£3,000) is work in progress. These figures should then be adjusted to reflect any likely losses, discounts, delay in payment or cost of difficulties expected to arise in completing the contract. Any progress payments received should be treated as creditors in accordance with SSAP 9.
Also further guidance at
So do you have Work in Progress or Amounts Recoverable on Contracts?