The Uddingston company, owned by Belgian insurer Ageas, saw its revenue slide by 21 per cent from £47.16 million to £37.22 million, with policy numbers dipping by around 95,000 to 891,502.
Pre-tax profits came in at £1 million for 2013, down from £2.27 million in 2012, according to accounts filed at Companies House.
Writing in the accounts, the directors said: "The amount of turnover drives the overall size and profitability of the company. Revenue has fallen over the last two years as a result of increased competition in the market, particularly for new business customers through online trading.
"Regulatory changes in the year, particularly the handling of customer claim data, also adversely impacted revenue."
Average staff numbers dipped from 841 to 764, with reductions in the numbers of both sales and support employees.
Directors' emoluments and pension contributions increased from £335,750 to £501,240, with the highest paid seeing their remuneration package rise to £249,675, from the £177,612 recorded in the previous year.
Jason Banwell, managing director, said the Kwik-Fit business has seen its core policy numbers increase every month in 2014.
It is planning to hire 50 new staff in Lanarkshire across its sales and customer service areas in the coming months.
Ageas UK's first-quarter loss in 2014 was £4.6 million as a result of weather-related costs, compared to a profit of £19.4m in 2013.