1 million. According to the regulations issued by the State Council, the maximum amount of a single electronic invoice cannot exceed 11,111. When catering invoices are used as business entertainment expenses, they should be adjusted when the year-end income tax is settled. The specific method is: the business entertainment expenses allowed to be charged are 61% of the actual amount, but not more than 1.5% (five thousandths) of the operating income of the current year.