The research by hospitality recruiter The Change Group found this was the equivalent of a £4,215 pay rise in one year and as a result, pay for a hospitality employee in London, working back of house now stands at £32,674 a year.
At the same time, average front-of-house salaries dropped for the second year in a row, falling by 3.7% or £1,168.
The average front-of-house salary is now £30,051 a year. Front-of-house salaries also dropped by 3.2%, or £1,045, in 2017 meanwhile, back of house rose by 3.5% in 2017.
However, average annual salaries for bar and pub employees rose 4.5% or £1,274 to just over £29,672 a year during 2018.
As a result of these increases, back-of-house salaries are now the highest in London at £2,623 more than the average front-of-house salaries and £3,002 more than the take-home pay for most pub and bar staff.
This is in stark contrast to two years ago when back-of-house salaries were the lowest with chefs typically earning £4,767 less than front-of-house employees and £794 less than the average wage for pub and bar staff.
The Change Group said one factor in the rise of back-of-house salaries could be an increasing willingness to negotiate pay.
A recent survey from the recruiter into attitudes on pay including 257 people working in the industry, showed hospitality workers were much more confident about negotiating pay and many were receiving large annual rises.
It found more than half (58%) of respondents had negotiated a pay rise that was above what the employer was planning to offer them.
While typically, hospitality workers negotiate a pay rise when moving jobs (28.8%) and at a promotion (29.5%), almost one in five (19%) negotiated pay increases at regular intervals.
Almost half (45.1%) had negotiated a salary increase in excess of 10% and 11% had achieved a pay rise of more than a fifth (20%).
It also highlighted a broad spread in the level of pay rises employees were receiving, with one in eight (12.5%) getting £3,000 or more and one in 15 employees receiving more than £4,500.
However, at the other end of the spectrum, one in four hospitality workers received less than a £1,000 increase in their previous pay review.
The Change Group co-founder Jim O’Brien said: “There has been a significant adjustment in chef salaries over the past two years, which is a good thing.
“Our research shows more and more employees are asking for regular pay increases and not waiting for a promotion or moving to a new job before asking for more money.
“The decline in average front-of-house salaries is partly due to the fact that businesses are creating more opportunities for junior employees. Overall, we are seeing an increase in the number of candidates registering at Change.
“Overall, hospitality businesses in London need support in order to ensure they get the right people for the job and candidates are carefully checked to ensure they fit the right requirements.
“It is vital the industry works hand in hand with Government and education to showcase hospitality is a fantastic career and offers a wide range of opportunities for people with different talents.”