Accumulator mechanics
The combined decimal price is produced by multiplying the price of each leg. One losing leg normally loses the full accumulator; a void leg is usually removed and the price recalculated under house rules.
Accumulator versus Bet Builder
BetMGM's Bet Builder is documented. A standard accumulator combines outcomes from different events; a Bet Builder combines compatible outcomes from one event.
Offer restrictions
New UK customers only, 18+. Select the Sports Welcome Offer, deposit and place a qualifying bet of £10+ within 7 days of registration at min odds 1/1 (2.0). Each-way qualifying bets: win part must be £10+ (£5 E/W does not qualify). Bet Builders count as one bet — combined odds must be 2.0+. Excludes virtual sports, e-sports and non-UK/IE horse racing. Void, cashed-out or partially cashed-out bets, multiples, Free Bets and Profit Boosts do not qualify. Receive 4 x £10 Free Bets on settlement: 2 x £10 Sports and 2 x £10 Bet Builder Free Bets (min odds 3/1 (4.0)). Free Bets expire 7 days after being awarded and cannot be used on e-sports or non-UK/IE horse racing. Activating the Sports Welcome Offer excludes you from the Casino Welcome Offer. Full T&Cs apply. begambleaware.org. Check whether a promotion requires a minimum number of legs or minimum price per leg.
Sources checked
Operator-owned information reviewed 1 August 2026. Product pages and terms can change.