A refund offer gives your stake back, usually as a free bet, if your selection loses. Lay it fully and the refund only comes if the bookmaker bet loses. Lay a little less, called underlaying, and you lock in roughly the same result either way, based on what the refund is worth to you.
How refund offers work
Typical refunds pay a free bet if your horse finishes second, or if your team loses. The refund is a free bet, not cash. Once it arrives, you can lay it as a normal free bet and keep around three quarters of its value.
Full lay or underlay
Say the offer is money back as a £10 free bet if your selection loses. You back £10 at 5.0, the lay price is 5.2, and you expect to keep 75% of the free bet, so it's worth £7.50.
| Approach | Lay stake | If it wins | If it loses (including refund) |
|---|---|---|---|
| Full lay | £9.65 | -£0.54 | £6.96 |
| Underlay | £8.20 | £5.54 | £5.54 |
A full lay keeps the refund as a bonus that only arrives if the bet loses. The underlay takes a smaller, steadier result either way. Over many offers, both average out about the same. The underlay just swings less.
Working out the underlay
Take the refund's expected cash value off the back stake times the back odds, then divide by the lay odds minus commission. Here that's (10 × 5.0 − 7.50) ÷ (5.2 − 0.02).
Underlaying only works if the refund arrives. Check exactly what triggers it, such as "loses" against "finishes second", and whether you have to opt in.
Finding refund offers
Refunds are among the most common offers for existing customers, especially on racing. They're easy to miss if you check bookmakers one by one.
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Questions people ask
What does underlay mean in matched betting?
Laying less than the full lay stake on purpose, so you win more when the bookmaker bet wins. You do it when something extra, like a refund, comes only if the bookmaker bet loses.
What retention should I use for a free bet refund?
Around 70% to 80% is typical for a stake not returned free bet laid at mid odds. Use what you usually get.
Should I always underlay refund offers?
No. A full lay is simpler and you don't depend on the refund arriving. Underlaying evens out your results when you take lots of offers.