Whether we’re taking advantage of a welcome bonus or an existing customer promo, it’s almost always better for us if the bet wins at Betfair and loses at the bookie. Here’s why:

• Bookies like losing punters. If we lose our entire balance, there’s a higher chance we’ll be offered another deposit bonus to tempt us back.
• Withdrawals from Betfair are quick and risk-free. Withdrawing from a bookie can trigger an account review, which may lead to a ban or stake restrictions. Betfair doesn’t care how often you withdraw.
• We want a healthy Betfair balance. It allows us to place larger lay bets at higher odds. Money sitting in a bookie account isn’t working for us—it’s just waiting to be rolled over or stuck.

Still, we don’t get to choose where the money goes. Even a 20/1 shot will come through occasionally, and when it does, it’s not ideal for us.

SO, WHAT IS UNDERLAYING?

Underlaying is a strategy where you deliberately lay less than the standard matched betting calculator recommends. This shifts your profit distribution so that if the bet wins at the bookie, you make more money—and if it wins at Betfair, you make slightly less.

This approach can be especially effective at higher odds. By laying a few dollars less than the calculated amount, you can reduce the sting of a win at the bookie.

There are two common ways to underlay:

• Flat Underlay: Lay a fixed dollar amount below the calculator’s suggestion.
• Percentage Underlay: Lay a percentage less than the suggested amount (e.g., 10% underlay).

WHY UNDERLAY?

• Reduced Commission at Betfair: By laying slightly less, your Betfair win (when it happens) is smaller—and so is the commission you pay. Over time, this can add up.
• Compensate for Inconvenience: A win at the bookie can mean delays, wagering complications, or unwanted attention on your account. Underlaying helps compensate for that hassle with a bigger payout.

For example:
Say you have a $50 bonus bet. You find odds of 10.00 at the bookie and 10.50 at Betfair. The calculator tells you to lay $43.06. But you choose to underlay and lay only $40.

• If the bet wins at Betfair: You make around $38 profit.
• If the bet wins at the bookie: You make around $70 profit.

That extra $32 makes a win at the bookie much less annoying.

A WORD OF CAUTION

Underlaying increases variance. You’re giving up some guaranteed profit for the chance of a bigger return. If you underlay too heavily and get a string of Betfair wins, your overall profit may take a hit.

Always run the numbers using our advanced matched betting calculator to see how different underlay amounts will affect your expected outcomes.

TRY IT OUT

Underlay your next bonus bet. Start small, and experiment with different underlay levels until you find a balance you’re comfortable with. It’s a great way to smooth out the annoyance of a bookie win—plus it increases your expected value by reducing your commission costs.