Johnny Depp is suing his former business managers alleging they mismanaged his earnings throughout his career, although the company says the actor's "irresponsible" spending is to blame.

Depp's lawsuit filed in Los Angeles Superior Court against The Management Group seeks more than $US25 million ($33 million), alleging its owners, Joel and Robert Mandel, failed to properly pay his taxes, made unauthorised loans and overpaid for security and other services.

The complaint, which is 52 pages long, states that "Mr Depp lost tens of millions of dollars and has been forced to dispose of significant assets to pay for TMG's self-dealing and gross misconduct."

The company represented Depp from 1999 until March 2016, receiving 5 per cent of his income from hit films including Charlie and the Chocolate Factory, Alice in Wonderland and the Pirates of the Caribbean franchise.