Small energy supplier Bulb is doubling its referral bonus this week, meaning both new customers and those who refer them can get £100 bill credit each. Its tariff, though not fixed, is already very cheap - and for most, if you factor in the referral bonus it significantly beats the market's cheapest.

Bulb, which hit 200,000 customers this week and has been around for two years, launched the week-long offer on Monday, raising the usual £50 it pays existing customers and the newbies they refer to £100.

How does the tariff stack up?

Bulb only offers one tariff - Vari-Fair. Here are the key need-to-knows:

  • It costs an average £855/year based on typical use, nearly £280/yr less than the average big six standard tariff. In comparison, the cheapest on the market is an average £830/year - so if you take the £100 referral bonus into account too, for many Bulb will win. Always do a full comparison to check your cheapest though.
  • Bulb has top service - it got 93% 'great' in our customer service survey (though there were only 27 votes) and has a 9.8/10 rating on the Trustpilot website (from 3,536 reviews).
  • Bulb will pay any early exit fees with your current supplier if you switch to it - up to a max of £120 - by crediting your Bulb account.
  • The tariff is variable, so you won't get certainty on the rates you pay for your gas and electricity. By contrast, other small, cheap providers offer fixed tariffs, letting you lock in your rates and guard against price rises. Bulb has cut its prices twice this year though, and if Bulb's prices do go up, you'll get 30 days' notice.
  • There are no exit fees to pay if you want to switch away.
  • The tariff's for dual-fuel or electricity-only, and you'll need to pay by monthly direct debit and opt for paperless bills - so you can't get it if you're on prepay or gas-only. Plus, it's 100% renewable electricity and 10% renewable gas.
  • No Warm Home Discount. Bulb's not currently part of the Government scheme, so even if you're eligible you won't get the £140 discount on your electricity bill with it.

'For most with the bonus it substantially undercuts the cheapest'

Martin Lewis, founder of, said: "Normally you have to be careful with referral deals like this, as they lead you towards the short term cash rather than long term value. Yet this one from Bulb is a corker as it’s on an already very cheap tariff. 

"For most people (always do a comparison) with the referral bonus it substantially undercuts the market’s cheapest. Couple that with the top customer service rating and it’s a winner. 

"The only sacrifice is that unlike most cheap deals the rate isn’t fixed, so you don’t get surety that things won't change."

How do I get the Bulb deal and referral bonus?

Existing Bulb customers need to log in to their online account, click 'refer a friend' and send their unique referral link.

There's no cap on the number of people you can refer, but those you do will need apply to switch before 11.59pm on Monday 20 November to get the £100. If the switch is unsuccessful for any reason, you won't get the bonus.

The person receiving the code MUST go via the link provided to apply directly with Bulb to get the bonus.

If you receive a referral, make sure you do a Cheap Energy Club comparison first, though, to see how much this tariff will cost you.

If you decide to go ahead and switch, by applying directly using your friend's code, both you and your friend will get £100 credited to your Bulb account around three weeks after the switch. To be clear, you WON'T get the £100 bill credit going via Cheap Energy Club.

If you've an account with Cheap Energy Club and you switch directly with Bulb, you'll need to update your account to let us know, so we can keep searching the market for you to see if you can save.