How many players are on a team, and how long is a match?

Under The FA's Walking Football Laws (February 2025):

• Substitutions are unlimited, and a substituted player can come back on. They are normally made when play is stopped; the player coming off leaves by the nearest boundary before the substitute enters.
• Match length: two to four equal periods of between 5 and 30 minutes each, with no more than 5 minutes between periods (competitions can play it straight through without a break).
• Goals: 3-5m wide and 1.2-2m high.
• No offside.
• A match shouldn't count if a team is permanently reduced (by sendings-off or players unable to continue) by more than two players in 5- or 6-a-side, or more than three in 7-a-side.