David Copperfield Sues Accountant Over Taxes

David Copperfield may have his next assistant for the "sawing in half" trick -- because the magician claims his accountant screwed up his taxes, costing him $471,000.

Copperfield is suing Robert Baral ... claiming the guy didn't file the magician's Canadian tax returns for 2008 and 2009, and also didn't let him know the previous accountant failed to file a 2007 return.

Copperfield also claims the accountant hired a Canadian firm to deal with the tax snafu and failed to monitor them to ensure things were handled properly.