Barton was keen to be involved in the 'Game 4 Grenfell' that will be hosted by former club QPR in September to raise money to help those affected by the recent tragedy.
But the 34-year-old revealed via Twitter on Friday morning how he had been apologetically turned down by the organisers because it will be an 'FA sanctioned' game and therefore an event which clashes with his ongoing suspension.
Barton shared an email sent to him which read, "Thank you so much for your generous offer to play in the GAME4GRENFELL. Unfortunately, the game is to be FA sanctioned, and to that end they have informed me that you will not be allowed to play in it due to your current ban.
"I just wanted to say that I am personally very sad about this and I am also incredibly grateful to you for your generous offer for your time, particularly on your birthday."
Barton was asked to keep the matter confidential as the match hadn't been publicly announced at the time of the email, and he chose to go public after the event was announced.
"I would have loved to be supporting the #Game4Grenfell at Loftus Road but the FA have decided my ban extends to helping a great cause. So unfortunately, unless someone engages their brain, I won't make it," Barton tweeted alongside the email.
Barton was found guilty of breaching FA regulations on gambling in April this year after allegedly placing in excess of 1,200 bets on football over a 10-year period. He was banned for 18 months until but will now only serve 13 months and will be eligible to return to football in June 2018.
It remains to be seen if he intends to continue his career at that point.