Birmingham City will lose out on a financial jackpot if they fail to make it into the Premier League – and the knock-on effect on the city’s economy would be worth millions, experts have said.

If promoted, the club can expect its turnover to soar next year and business leaders say there would be a knock-on effect to spending and a boost to the city’s profile for having two top-flight clubs.

The club’s annual revenues rocketed from £25 million to £49.8 million last time the team reached the top-flight, in 2007, and a similar rise is expected again.

But the team missed out on a chance to go up this weekend after they lost 2-1 to Preston, and the city will be on tenterhooks to see if Blues make it up on the last day of the season next Sunday.

Roger Allonby, head of tourism and culture at regional development agency Advantage West Midlands, said as well as bringing millions of pounds more spending on tourism and retail, the promotion would also improve the city’s international standing.

Mr Allonby said: “The Premier League is recognised as the best and most competitive league in the world. Not only does the promotion bring pounds and pence here, the international profile it brings is massive.

“Places like Manchester have seen their international perception grow through Manchester United, so having Aston Villa doing well and Birmingham City back in the Premier League is a great way of improving perception of the West Midlands.

“There will also be more people coming to the city for games, which means more people staying here and more people spending money.”

Birmingham City’s attendance statistics in recent years will also cheer its board of directors. Since 2001, the club has averaged 21,845 ticket sales per game in three seasons in the second flight, while in five Premier League seasons it has averaged 28,036 – which means more than 6,000 new fans through the doors.

Birmingham Chamber of Commerce press and PR manager John Lamb said the latest success would give a timely boost to the region’s private sector.

He said: “From a business point of view the feelgood factor is quite important. The Premier League is massive and I don’t think the Championship gets the same sort of global exposure.”

The financial might of the Premier League was shown in Deloitte’s Football Money League survey published in February.

While Spanish giants Real Madrid were named the world’s richest club, seven of the top 20 earners were Premier League clubs.

The richest, Manchester United, turned over £325 million in 2008, and Chelsea, Arsenal, Liverpool Tottenham Hotspur, Newcastle United and Manchester City all turned over more than £100 million.

Alex Byars, consultant in Deloitte’s Sports Business Group, said promotion for Birmingham City would be the “biggest financial prize in world football”, worth around £60 million.

He said: “Enhanced commercial revenues and higher gate receipts in the Premier League are likely to generate an additional £5 million for promoted clubs, based on recent experience.

“Over the past decade half of the 30 newly promoted clubs have retained their Premier League status at the end of their first season in the top flight.”

Tony Joynson, project manager of inward investment company InStaffs, said the region would become more attractive to investors if Blues became the fourth top-flight club in the region – after Aston Villa, Wolverhampton Wanderers and Stoke City. He said: “Birmingham City carries the name of the city, unlike Aston Villa, so it is absolutely essential the club is in the top-flight.”