Wiktionary
overbilling
vb. (present participle of overbill English)
Wikipedia
Overbilling
Overbilling (sometimes spelled as over-billing) is the practice of charging more than is legally or ethically acceptable on an invoice or bill.
Usage examples of "overbilling".
On the other hand, if she claimed she hadn't done the legal work on IDC, it would raise questions about overbilling her client - possibly landing her in the same soup as Webb Hubbell, whose overbilling had resulted in a criminal conviction and time in federal prison.
As a defense contractor, Platt & Rockland had a rich history of cost overruns, overbilling, and false claims.