This compares to the £10.3bn collected in the previous year, showing a 27% increase, said national accountancy group UHY Hacker Young.
The group said the jump is partly attributed to the introduction of the loan charge forcing any individual who had used tax avoidance schemes to pay any owed charge to the taxman or face extra penalties.
This is estimated to have hit around 50,000 people who had to pay back up to 20 years of income, with some receiving bills stretching into hundreds of thousands of pounds.
Additionally, a high level of cash was also recovered thanks to HMRC’s overseas tax campaign in 2018.
It required people to declare any overseas income or gains by September 2018, pay any liabilities or risk being hit by penalties as high as 200% of the sum owed.
Mark Taylor, head of tax investigations and dispute resolution at Buzzacott, told International Adviser: “HMRC’s Requirement to Correct legislation and draconian Failure to Correct penalties for offshore non-compliance, coupled with tax avoidance users urgently wishing to settle to avoid the pending loan charge legislation, has undoubtedly increased Treasury coffers.
“However, while HMRC may well be pleased with the published compliance figures and patting themselves on the back, one must question how much of the £13bn yield is real cash. HMRC officers now not only record the yield taken from the enquiry and earlier years but also consider Future Revenue Benefit (‘FRB’).
“FRB is where the HMRC officer looks into their crystal ball to predict the yield in future years that but for their enquiry/intervention would not in their opinion be declared/paid to HMRC. FRB will explain why the cash collected is far less than the compliance yield.
“I am aware of cases where the HMRC officer’s predicted FRB figure has been rejected by management after internal review due to the estimates being claimed were held to be excessive. FRB is vital for HMRC compliance directorates to hit challenging targets.”
UHY Hacker Young agrees with Taylor as it said that actual cash makes only up to 38.5% of the overall £34bn HMRC claims to have collected.
The remaining 61.5% comes from “hypothetical estimates”, including the FRB.
Clive Gawthorpe, partner at UHY Hacker Young, said: “Although HMRC will be pleased that cash collected from investigations has jumped, the majority of that yield is questionable.
“Overall, almost two thirds of HMRC’s yield from investigations isn’t actual cash, it’s purely hypothetical and could just be a figure plucked out of thin air.
“Over the last couple of years, HMRC has used a huge variety of sophisticated measures to help boost cash collected from investigations. Technology is playing an increasingly important part in identifying cases and its integration into the compliance process is set to continue.”