His Rangers contract was terminated due to training ground row
Joey Barton has been charged with misconduct, with the Football Association claiming the midfielder placed 1,260 bets in the past 10 years.
The FA says he broke rules by betting on "football matches or competitions" between 26 March 2006 and 13 May 2016.
Barton, 34, is set to rejoin Burnley in January, having left Scottish Premiership side Rangers in November.
In the same month, he was given a one-match ban for breaking Scottish Football Association rules on gambling.
Barton admitted the Scottish FA charge of placing 44 bets between 1 July and 15 September, while he was a player at Ibrox, and his suspension will carry over into his Burnley career.
He has until 5 January to respond to the FA charge.
Barton can be registered and play for a club while the investigation is ongoing, but will next be available for Burnley in their Premier League home game against Southampton on 14 January.
What are the rules on betting?
The FA brought in new rules in 2014 which ban players and staff at clubs down as far as the eighth tier of the English men's football pyramid - as well as at clubs in the Women's Super League - from betting on any football match or competition anywhere in the world.
Players and staff are also prohibited from betting on football-related matters, such as player transfers, the employment of managers or team selection.
That outright ban on football-related betting applies to all involved in the game from Premier League level down to - and including - the Northern Premier, Southern and Isthmian Leagues.
Previously, participants were prohibited from betting on a match or competition in which they were involved or could influence.
Barton has been charged with offences allegedly committed under both the new and old rules.
His Rangers contract was terminated following a training ground row which led to a falling out with manager Mark Warburton and he played just eight games for the club.
Barton began his career at Manchester City in 2001, joined Newcastle in 2007 and then signed for QPR in 2011. He had a loan spell with Marseille in France for 12 months, before joining Burnley for the first time in August 2015.
Why has it taken 10 years to come to light?
It is understood that the FA was only made aware of the bets by the betting company in the last few months, which led to its investigation.
The number of bets have resulted in a detailed and complex investigation and the timing of the charge is not related to Burnley's announcement that Barton is to rejoin them.
Barton was expected to have been charged even if he had remained a free agent.
Burnley said they are "discussing the matter with Joey and his legal representatives".
