overbill
From Longman Business Dictionaryoverbillo‧ver‧bill /ˌəʊvəˈbɪlˌoʊvər-/ verb [intransitive, transitive]ACCOUNTING to send an invoice to a customer for a higher amount than what they really oweHe has been accused of fraudulently overbilling the organization by $100,000. —overbilling noun [countable, uncountable]Money from the overbillings went to pay for his lavish lifestyle.