Thank you for your response. From the guidance that you provided, I see how receipts must be retained for expenses made up to 5 April 2019. What about after this point? From the guidance:
From 6 April 2019, employers will no longer be required to operate a system for checking an employee’s expenditure in order to make payments free of tax in relation to expenses paid or reimbursed using benchmark scale rates. Instead, employers will only be required to ensure that employees are undertaking qualifying travel on occasions in respect of which a payment is made or reimbursed and that neither the employer nor any other person knows or suspects or could reasonably be expected to know or suspect, that travel was not undertaken. See EIM30225.
Is it then sufficient to document that I have been travelling for work in order to claim relief up to the meal allowance or per diem rates?