The 28-year-old has been the number two to Manchester City's Joe Hart since last year's World Cup but has had a series of injury problems and has made the decision to benefit his club career.
Foster told www.bcfc.com: "Performing at the highest level game in, game out, and particularly when there's been as many matches as there have been this season, really takes it out of your body."
Foster's decision, which he insists is reversible, comes exactly a year after he was left out of the England squad for the World Cup by coach Fabio Capello.
He said: "It's no secret that I've had a few niggling injuries and that I've had to pull out of the past few England squads because of that.
"I've spoken to the management team and coaches here at Blues and told them what I want to do but it's also very important that I say just how much I have loved playing for England and being part of the set-up."
Source: PA
Source: PA