Your problem doesn't actually exist. If you list meals as a company cost, then you obviously need an invoice. The current situation is that the food expenses are not your expenses, and your company is right in the middle, deducting money from employees' salaries and then paying the money to a third party. In this case, an invoice is not needed at all. Invoice is the original voucher necessary to collect fees. Your business does not involve cost at all. It is enough to have a salary slip to prove that there is a deduction and a canteen receipt to prove that the money has been paid.