Offer types explained: free bets, early payouts and acca refunds

Checked on 6 November 2026.

Bookmaker promotions come in a few common shapes. This page explains four of them in plain terms. It does not list live offers. Match Sterling has no live offer list, and no paid bookmaker referral links are active on this site.

Every example below is illustrative only. The prices are made up for learning. Bookmaker A is a made-up bookmaker and Exchange B is a made-up betting exchange (a site where people back and lay against each other). Every example uses 2% exchange commission (the fee an exchange takes from net winnings). Put your own figures into the calculator before you bet.

New to the words? Read the beginner guide or the glossary first.

The two formulas used on this page

A back bet is a bet that something will happen. A lay bet is a bet that it will not happen. Liability is what you lose on the exchange if the selection you laid wins.

For a cash bet or a stake-returned free bet:

lay stake = back stake × back odds ÷ (lay odds − commission)

For a stake-not-returned free bet:

lay stake = free bet × (back odds − 1) ÷ (lay odds − commission)

In both cases, liability = lay stake × (lay odds − 1). Commission is written as a decimal, so 2% is 0.02. These are the same formulas the calculator uses.

Free bets

A free bet is a promotional bet that a bookmaker adds to your account. It usually arrives after you place a qualifying bet. A qualifying bet is the normal cash bet you must place to unlock the reward.

You usually lay the qualifying bet on an exchange. Win or lose, you then take only a small qualifying loss.

Illustrative qualifying bet. You back £10 at 2.00 with Bookmaker A. You lay at 2.04 on Exchange B.

• Lay stake = 10 × 2.00 ÷ (2.04 − 0.02) = 20 ÷ 2.02, about £9.90
• Liability = 9.90 × (2.04 − 1), about £10.30
• If the selection wins: +£10.00 at Bookmaker A, −£10.30 at Exchange B, so about −£0.30
• If the selection loses: −£10.00 at Bookmaker A, +£9.90 × 0.98 at Exchange B, so about −£0.30

Every result is covered here, because the back and the lay are on the same selection and market. The £0.30 is the cost of unlocking the free bet.

Before you start, read the offer terms. Check the minimum odds, the markets allowed, the expiry date and whether the free bet is SNR or SR.

SNR and SR free bets

SNR means "stake not returned". If an SNR free bet wins, you get the winnings only. A £10 SNR free bet at 5.00 pays £40, not £50. SNR is the more usual type.

SR means "stake returned". If an SR free bet wins, you get the winnings and the stake. A £10 SR free bet at 5.00 pays £50. SR is the less usual type, so check the wording.

The two types need different lay stakes. Use the matching setting on the calculator. The longer guide is SNR vs SR.

Illustrative SNR free bet. A £10 SNR free bet at 5.00 with Bookmaker A, laid at 5.20 on Exchange B.

• Lay stake = 10 × (5.00 − 1) ÷ (5.20 − 0.02) = 40 ÷ 5.18, about £7.72
• Liability = 7.72 × (5.20 − 1), about £32.42
• If the selection wins: +£40.00 − £32.42, about +£7.58
• If the selection loses: £7.72 × 0.98, about +£7.57

That keeps about 76% of the £10 face value at these prices. This share is called the rating or retention. It is an estimate for these prices, not a promise.

Illustrative SR free bet. The same prices, but the stake comes back on a win.

• Lay stake = 10 × 5.00 ÷ (5.20 − 0.02) = 50 ÷ 5.18, about £9.65
• Liability = 9.65 × (5.20 − 1), about £40.53
• If the selection wins: +£50.00 − £40.53, about +£9.47
• If the selection loses: £9.65 × 0.98, about +£9.46

You keep more with SR. You also need more cash on the exchange.

Odds change the SNR result. The same £10 SNR free bet backed at 3.00 and laid at 3.10 gives a lay stake of 20 ÷ 3.08, about £6.49. The liability is about £13.63. The result is about +£6.37 either way. Lower odds need less exchange cash but keep less of the face value. See lay liability for how much cash to keep on the exchange.

Early payout offers

An early payout offer is a bookmaker promotion that can settle your back bet as a winner before the event ends. The bookmaker sets the conditions in its own terms. Read them before you bet.

The exchange does not pay out early. It settles the lay on the final result. So, if the bookmaker pays out early and your selection then fails to win, both bets can win.

Illustrative early payout example. These are placeholder figures. Assumptions: a cash back bet on a single selection, the lay fully matched before the event starts, the early payout settles the full back bet as a winner and the exchange settles on the final result.

You back £10 at 3.00 with Bookmaker A. You lay at 3.10 on Exchange B.

• Lay stake = 10 × 3.00 ÷ (3.10 − 0.02) = 30 ÷ 3.08, about £9.74
• Liability = 9.74 × (3.10 − 1), about £20.45
• If the selection wins: +£20.00 − £20.45, about −£0.45
• If the selection does not win and there is no early payout: −£10.00 + £9.74 × 0.98, about −£0.45
• If the bookmaker pays out early and the selection then does not win: +£20.00 at Bookmaker A and +£9.55 at Exchange B, about +£29.55

The first two lines are the usual cost of the bet. The third line only happens if the offer's conditions are met and the result then turns. You cannot count on it.

Acca refund / insurance offers

An accumulator, or acca, is one bet on two or more selections. Every leg must win for it to pay. An acca refund / insurance offer is a bookmaker promotion that gives something back if your acca loses because of one leg. What you get back, and the rules for getting it, are set in the bookmaker's own terms. Read them before you bet.

Laying an acca is harder than laying a single bet. The Match Sterling calculator handles one back and one lay. For a multi-leg acca, you lay each leg separately, which is awkward. The other option is to use a manual acca tool once one is live on this site. It is not live yet.

Illustrative refund value only. This is a placeholder. Assumption: the refund is a £10 SNR free bet and you use it at the prices in the SNR example above (5.00 back, 5.20 lay). That free bet would keep about £7.57 to £7.58, as worked out above. This figure does not include the cost of laying the acca legs, so it is not the value of the whole offer.

Before you use any offer

• Read the full terms. If they are unclear, skip the offer.
• Check that the exchange has enough money waiting at your lay odds to match your full lay.
• Place the back bet, then lay straight away.
• Check that the liability on the exchange matches the calculator.
• Record the result in the profit log, which stays in your browser.

Matched betting still involves real bets and real money. Odds can move, lays can be part-matched (only partly taken on the exchange), mistakes cost money and bookmakers can restrict accounts. For a full first run, follow the first-offer walkthrough.

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