The tricky Mansfield Town winger has joined the club’s National League South challenge.
Potter is no stranger to the Blues’ league having appeared in Step 2 for AFC Wimbledon and Havant & Waterlooville.
Potter, 29, steps out of League Two after ending his time at Field Mill.
He could feature for his new side in their game on Tuesday night against Concord Rangers.
Billericay got off to a great start to the new season when they beat Truro City 4-0 on Saturday.
Manager Harry Wheeler told The Echo: “I’m really pleased to sign Alfie. I like covering all places with two quality players and now I have two left and two right sided midfielders in the squad.
“He is very intelligent and could be compared to a wide version of Sam Deering, although Sam can also play out wide.
“He comes off the line and is very much a League player, like Callum Kennedy. That is proven by the offers he had this summer so for us to get him really is something.”