British Gas is giving customers ‘unlimited’ Amazon vouchers worth £50 each as part of a rewards programme.

The major energy supplier, which serves around 10 million homes in the UK, is offering gift cards to customers every time they refer a friend.

The value of the gift card is dependent on what your friend buys, with £50 up for grabs when they switch their gas and electricity or £25 when they switch just one.

You need to be an existing British Gas customer with a home energy account to take part in the scheme, and you’ll need to have an online account with the supplier.

To refer a friend you simply need to access your online account and you’ll be given a unique referral link which you can send to as many friends as you like.

So if you sent the link to five friends and they each switched their gas and electricity, you could bag £250 worth of free Amazon vouchers, while if 10 friends signed up you’ll get a whopping £500.

To be eligible for the reward your friend must use your unique referral link to switch their energy to British Gas so the supplier knows you have referred them.

Once they’ve completed their purchase British Gas will verify their details and you’ll be sent your Amazon gift card via email within 90 days.

There is no limit to the number of friends you can refer to as you'll get a reward for every friend you get to switch - so the more people you get to sign up the more you’ll earn.

British Gas said: “The value of your Amazon.co.uk Gift Card depends on what your friend buys. And the best part? You can refer as many friends as you like through our refer a friend scheme – and get rewarded for each one.

“Spread the word and refer your friends by accessing your unique referral link in your online account. Whether you email it, tweet it, or share it on Facebook, you can choose whatever works best for you.

“Once they’ve joined us, you’ll both get an Amazon.co.uk Gift Card worth up to £50 each.”