Working in construction without an advance is risky — materials must be bought before work starts. An advance invoice is the proper way to request prepayment.
How to format it
- state clearly that it is an advance (prepayment) invoice;
- reference the contract or estimate it relates to;
- the advance amount — usually 30–50% of the contract sum or the material cost;
- payment term and bank account.
In the final invoice the advance appears as a negative line, so the client sees the full value, the paid advance and the balance. VAT payers note: the VAT obligation arises when the advance is received, so show VAT as usual. Back the amount with an estimate from the estimate generator.