If you do not have receipts for an overnight stay, you should be aware of the following: If it is certain that overnight costs have been incurred, they may be estimated (H 9.7 LStR; BFH ruling of 12.9.2001, BStBl. 2001 II p. 775). As an estimated amount, you should use the amount that the employer is allowed to reimburse tax-free - and this is 20 Euro per overnight stay.
For overnight stays abroad, breakfast is usually not included in the invoice price. In this case, the Federal Ministry of Finance considers "a handwritten note by the business traveller on the hotel bill to be sufficient to confirm that no breakfast is included in the overnight costs" (BMF letter of 5.1.2001, DStR 2001 p. 621).
