It has been a record-breaking year for film production in the UK, as international filmmakers have flocked to British shores to take advantage of tax breaks.

Figures released by the BFI show that US studios are filming an increasing number of multimillion pound blockbusters in the UK, from the rebooted Star Wars franchise to Mission Impossible 5 and Joe Wright’s fantasy epic Pan, generating over £1.4bn in 2014.

That is a 35% increase in revenue on the previous year and the highest since the BFI began collecting records 20 years ago.

The significant boost in investment has been attributed to the generous 20%-25% tax break now offered to feature productions with a budget of £20m or more, who opt to film in the UK and fulfil a set of cultural criteria ensuring the money will be injected back into the British economy.

The tax benefits have proved popular among many big American film studios which are increasingly choosing to produce their big-budget blockbusters in UK studios such as London’s Pinewood.

It is understood to be a key reason why Disney and Lucasfilm are currently making all three planned Star Wars films in the UK, even prompting them to open a new London base for Industrial Light and Magic, the post-production studio responsible for the special effects.

Ben Roberts, director of the BFI film fund, said the figures were a testament to both the benefits of the tax credits, but also the quality of film and production crews in the UK. The fact that you’ve got tax relief combined with crews that are on top of their game makes it a very attractive place for the studios to come and make films,” said Roberts.

“We are known for having world class crews and that’s demonstrated itself this year more than any other before. And the number of people who have come up through the Harry Potter films, in terms of crew and craftspeople, has had a really long term impact on film-making.”

Roberts was confident the international investment in the UK was a trend that would only continue. “If you talk to Pinewood and the other studios they will tell you they have productions booked for the foreseeable future,” he said.

“Marvel and Disney have made a real commitment to the UK – they will be shooting more blockbusters here in the next year or so – and Warner are so confident in the UK they are building on Leavesden [in Hertfordshire], which is their own major studio to make films here in the future.”

The BFI emphasised that many of this year’s biggest blockbusters had been made on British shores, including Mission: Impossible 5 for Paramount, Avengers: Age of Ultron for Marvel, Tarzan for Warner Bros, Alice In Wonderland: Through the Looking Glass for Disney as well as the new James Bond, Spectre.

Total spending by big US studios increased by £300m from 2013 and is now almost triple what it was in 2008.

It has been a similar story for big budget television dramas, which since April 2013 have been eligible for the same 20% tax breaks as films if they cost more than £1m per hour of television, and subsequently generated hundreds millions of pounds of revenue in 2014.

Opulent British productions such as the BBC’s Wolf Hall and ITV’s Downton Abbey, Foyle’s War and The Great Fire, as well as US-backed programmes 24: Live Another Day and Outlander, were all responsible for generating £615m in income in 2014. American television productions accounted for £287m.

With series five of HBO’s Game of Thrones being filmed in Northern Ireland this year, experts predicted the profitable momentum would continue.

Iain Smith, the chair of the British Film Commission who was also a producer on the latest series of 24, which was filmed in London for the first time, said the combination of tax benefits and talented crews had made the UK “probably the most important production centre in the world at the moment for television”.

“No doubt Fox TV would not have chosen London as the new location for 24 if the tax credit had not existed, which is what I think the statistics are showing is happening elsewhere,” Smith said.

“The tax credits are critical, they are a hook to bring international focus to the UK. Before this, American television very much tended to stay at home.”

However, he warned against taking the upward trend for granted, adding: “We are coming into more competitive times and other territories are waking up to the benefits of this. Ireland has just reactivated its whole support system for television, Canada is our biggest international rival I would say and South Africa is also coming upstream. So I would say we’ve got a fight on our hands.

“We are in as good a position as we can be to continue to harvest this business- but we shouldn’t rest on our laurels.”

Charles Moore, partner at UK media law firm Wiggin LLP, who was instrumental in lobbying for the introduction of the tax credit for high-end television shows, said the impact of the tax credits had exceeded his expectations.

“When we first started putting together an argument for the Government about introducing the tax credit, there were literally no international television productions in the UK apart from Game of Thrones,” he said.

“Before this tax credit, the UK was not really on the radar of anyone in TV outside of this country because of a lack of incentive, so to achieve that revenue in the first year exceeds all our original estimates. And that will only increase – I don’t think it will plateau by any means.”

The tax credits were not only proving an incentive for international productions, Moore added. “Also, before the tax credits, lots of UK television production was going overseas to access foreign incentives.”

“So the fact that there were 60 domestic productions filmed in the UK last year is an indicator that series that might previously have filmed somewhere like Hungary or South Africa are now staying in the UK.”