Public sector net borrowing ballooned to £8.8bn last month, marking the first January deficit for a decade.
The figure is £18.4bn more than in the same month last year and is the highest January borrowing amount since records began.
Public sector borrowing is now estimated to have reached £270.6bn in the first 10 months of this financial year, according to the Office for National Statistics.
This is £222bn more than the same period last year and is also the highest borrowing amount in any April to January period since records began in 1993.
Public sector net debt rose by £316.4bn over the first 10 months of the year.
It came as separate ONS figures showed retail sales dropped by 8.2 per cent last month compared to December due to the impact of the third national lockdown.
All brick-and-mortar retailers suffered a decline in sales, while online retailers continued their ascent.
Online sales soared to reach a record high of more than a third of total money spent.
Rishi Sunak is set to extend business rates relief, as well as other support measures such as furlough, into the summer, marking a boost for struggling companies.
The chancellor is expected to delay a final report on a review into business rates relief, which includes a potential online sales tax, until the autumn.