wicker cortex

AML(Anti Money Laundering) £250 charge to check client by my accountant. His accountancy company has changed from sole trader to Ltd company. He is today asking all clients to pay £250 to update our AML records. Otherwise he will cease representing us. Is this above board? is my accountant really allowed to charge every client £250 for something which is his financial responsibility as its his company causing the issue? Please help.