Lindsay Caldicott, 52, pleaded guilty to dishonestly appropriating around £520,000 from SPA Technique Ltd, in Tamworth Road, in Lichfield.
Stafford Crown Court heard that Caldicott was in a position of trust and managed the company's accounts.
She abused the trust to steal around £520,000 between October 2009 and June 2018.
She used the money to fund a lifestyle well in excess of her legitimate income.
Caldicott stole the money by transferring money from the business into bank and credit card accounts. She then covered up these payments by way of false accounting.
The court was told that in 2015 to 2016, the company was trading as SPA Automotive Ltd when it then went into liquidation – most likely as a result of the ongoing fraud which had not been discovered at that stage.
The fraud came to light towards the end of May 2018, shortly after which Caldicott resigned from the company.
In an interview with police, Caldicott admitted to stealing £478,000. She has repaid a significant amount of the stolen money through a civil settlement agreement.
Caldicott, of Poplar Gardens, in Burton-On-Trent, was jailed for 16 months at Stafford Crown Court.
Detective Constable Nicholas Gorman, of Staffordshire Police, said: “This was a serious and sustained fraud which was perpetrated over several years and caused significant damage to a business in Staffordshire.
"It was an appalling breach of trust and, although Caldicott has repaid part of the sum, we are glad she has been sentenced for her actions.”
Richard Barnes, managing director of SPA, said: “Lindsay Caldicott worked for me for over 24 years and was trusted with everything I had and considered a close friend. To find over two years ago she was guilty of stealing between £9k and £12k a month for years was a great shock.
“Good, hard working staff lost their jobs through her dishonesty. She perpetrated a clever fraud of keeping two sets of books that hid cash taken and that was allocated to unpaid suppliers.
"She had multiple new cars and a holiday home on the Yorkshire coast."