Although tax income in September was higher than last year, in part due to the increase in employers’ national insurance contributions, spending also increased.
This was partly due to pay rises and inflation increasing the government’s day-to-day running costs, as well as inflation-linked increases to state benefits.
The government also had to pay £9.7bn in debt interest, which was up by £3.8bn from the same month last year.
Public sector debt in the UK is now estimated to be at 95.3% of gross domestic product (GDP) and remains at levels not seen since the early 1960s.
Responding to the figures, Chief Secretary to the Treasury James Murray said the government would “never play fast and loose with the public finances”.
He reiterated the government’s aim of bringing down borrowing, to be rid of “costly debt interest, instead putting that money into our NHS, schools and police”.
But shadow chancellor Mel Stride said that borrowing was “soaring under this Labour government”.
“Rachel Reeves has lost control of the public finances and the next generation are being saddled with Labour’s debts,” he said.
Liberal Democrat Treasury spokeswoman Daisy Cooper said “alarm bells should be ringing for the government ahead of the Budget”.
She said the Conservatives had left the economy in “a terrible state” but that “this government has made mistake after mistake, failing to get our economy growing again”.
The new figures from the ONS include a correction to earlier data, when an error had been made in how VAT receipts had been added.