Emile Heskey remains Birmingham City's most expensive signing after joining from Liverpool for a reported £7.88m, but that is disputed.
Heskey had just come off a season where he had scored 12 goals in 47 games with the Reds. In his first season, he repaid the fee by netting 11 times in 38 games. Blues suffered relegation to the Championship in 2006 with Heskey only scoring five goals that term.
The 62-cap England international didn't stay around and was sold to Wigan Athletic for £5.5m. Managing director Karen Brady claimed because of Birmingham's relegation, they wouldn't need to pay the remaining £1.5m to Liverpool for him. If that's the case, then Ivan Sunjic and Jota both have claims to being their club record signing.
Jota signed from Brentford in 2017 on a four-year deal for a club-record fee of over £6m. Ivan Sunjic then arrived at St Andrew's two years later with a reported fee of £6.3m paid to Hadjuk Spilt to acquire his services, and in 2024 he is a free agent.
Whoever you regard as the club record signing, it's still been a few years since the club broke the bank to sign someone. Aberdeen striker Bojan Miovski has been linked, but he will cost a reported £7m, and it's highly unlikely that Birmingham in League One will be spending that kind of money as they look to rebuild under Chris Davies.
Nevertheless, Birmingham will have a vast amount of resources next season, and are arguably the biggest team in the division. The name alone along with the backing of Tom Wagner and Tom Brady will make them a pull with Ryan Allsop signing up to that.
Some clubs have yet to spend more than a million on a player, and that just goes to show the variety of teams in the division. Thanks to our friends at the Mansfield Chad, here are the record signings of all 24 teams in League One.

1.
Mansfield Town have paid a record £150,000 for three players - Lee Angol from Peterborough in 2017, Andy Cook (pictured) from Walsall in 2019 and Lee Peacock to Carlisle in 1997. Photo: Pete Norton

2. Huddersfield Town - £17.5m
Terence Kongolo signed for £17.5m from AS Monaco in the January window in 2018. Photo: Stuart MacFarlane

3. Bolton Wanderers - £10.9m
Bolton Wanderers signed Johan Elmander from Toulouse for £10.9m on 1st July 2008. Photo: Michael Steele

4. Birmingham City - £7.88m
Birmingham City signed Emile Heskey from Liverpool in the 2004/05 season for £7.88m. Photo: Stu Forster