Christopher Dudzinski, 49, of Dudzinski and Partners, Butts Court, Leeds, claimed thousands of pounds from the estates of late clients and ploughed the cash into his firm.
Investigators found he also told customers he was investing their money when in fact it was being kept in the firm's accounts.
Financial records were not properly written up and an investigation in 2006 revealed a £25,975 'black hole' in the client accounts.
Dudzinski accepted he withdrew clients' money before he billed them for his work, the Solicitors' Disciplinary Tribunal in London heard.
"A large part of the shortfall, £21,230, was in respect of costs transferred from client to office account in circumstances where bills had not been delivered to the client," said Jonathan Goodwin, for the Solicitors' Disciplinary Authority.
Dudzinski was acting for the executors of a will when he took £2,350 from the estate of a dead man after his affairs had been completed.
When questioned, the lawyer said he thought he deserved more for the work done previously.
He billed another estate for £2,350 and then took more than £5,000 more from funds the firm was holding.
"The balance went from £22,401, to £15,907 due mainly to the raising of more bills and costs after the estate accounts had been distributed and costs taken," Mr Goodwin said.
"He took costs in circumstances where he knew he was not entitled to them."
Dudzinski was supposed to invest £4,000 left to two children by their grandmother, but put the cash into his firm.
He told another client he was investing his £11,000 legacy and even sent a letter showing the sum invested and the "competitive interest" earned.
"The funds were in fact held in the firm's general bank account," said Mr Goodwin.
Dudzinski said he had wanted to put the money in a high-interest account but "kept putting it off'."
He failed to invest £165,000 another client had inherited, but again said he had placed the cash in a deposit account.
Dudzinski also paid £15,282 from one customer's account into another which had no connection with it when he "panicked" because there was a cash shortfall.
His lawyer, Mr Peter Johnston, said Dudzinski's marriage was under strain because of his dishonesty and he was in a "parlous financial state."
He had since resigned and had been working for another solicitor.
Dudzinski, of Wood Lane, Headingley, Leeds, admitted nine allegations including wrongly using clients' money and deliberately misleading clients.
Chairman Jeremy Barnecutt said: "It seems a sad case as is apparent from the letter from a partner at the firm who consequently employed Mr Dudzinski who says he is hard- working and conscientious."
Dudzinski was also ordered to pay £21,000 in costs.