Former Hereford midfielder has joined Northern Premier side Stourbridge.
Birch has been with Sutton Coldfield since leaving Hereford, captaining them this season.
Glassboys Boss Gary Hackett told the club's OS: "Aaron had a trial with us a couple of years ago but at that time he wasn’t physically ready.
"He did tremendously well at Hereford and had Football League scouts watching him.
"Aaron has been Sutton's best player this season. He's a clever footballer and I think he'll be a big bonus for us. He's comfortable on the ball and is looking to chip in with goals."