"Matthew "Billy" Beall signed professional forms for Cambridge United after successfully completing two years at The Abbey as a YTS trainee, although he started out with Norwich City as a schoolboy. He made his first team debut as a substitute in the Auto Windscreens Shield in September 1995 while still a trainee, making his full league debut in January. A diminutive but tough-tackling midfielder who never stops running, 'Billy' broke into the first team again in early March 1996 and held his place for the final fourteen games of the season. He was an immediate hit with the Cambridge United fans who likened him to former Abbey legend Steve Spriggs, and he scored five goals in the run-in to the end of the season. Until he was rested during the latter stages of the 1996/97 season he was a regular in the number 11 shirt, and considered a bright prospect.

Billy was linked with a move to Orient at the end of the 1997/98 season although Barnet and Peterborough were also rumoured to be interested in him. Orient returned with an increased offer resulting in a transfer dispute that stretched on into October 1998 where it went before a transfer tribunal. Billy then joined Orient for a rumoured fee of £50,000 and made his debut on 31st October against Scunthorpe in a 1-0 victory for the O's. The following Saturday, Billy scored his first goal for the Orient in their 1-0 victory at Hull. At this stage, he had made 81 league appearances for Cambridge.

Leyton Orient reached the Division Three play-off finals and took on Scunthorpe on 29th May 1999 at Wembley. Billy played in that match but the Orient lost 1-0 and so will remain in Division Three for another season. In February 2001, Billy joined Conference side Dover on a month's loan. Returning to Orient a refreshed player, he helped the 0s to a Division Three play-off final place but was an unused substitute in the 4-2 defeat at the hands of Blackpool. Billy signed a new contract with Orient in June 2001. However Billy didn't fit in with the plans of Orient's new manager Paul Brush and Beall's contract was terminated at the end of January 2002. Shortly afterwards Billy returned to Cambridge to join Dr Martens league side Cambridge City.

Billy left Cambridge City at the end of the 2001/02 season. He later had a trial with Darlington in August 2002. It's not clear where or how he spent the 2002/03 season but he materialised at Farnborough in July 2003 where he played against QPR on 12th July 2003 as a triallist. He obviously impressed and signed a contract with Boro two days later.

Despite making 40 appearances for Farnborough during 2003/4, his contract was not renewed at the end of the season and he departed from the club.