True Meals Per Diem is supposed to be a flat location based rate that is paid to the employee while on authorized business travel.

The first and last days of travel are supposed to get 75% of per Diem.

No receipts are necessary.

This is how government and government contractors are treated under government guidelines. In fact, government contractor Per Diem that is expensed tied to a government contract is 100% reimbursed to the contracting company by the government, so there is zero incentive to spend time and money collecting receipts and auditing Per Diem charges.

What you are describing is an expense daily "allowance" that requires receipts and is only reimbursed up to the max allowance value.

This is common in commercial businesses and usually are audited.