Over a million prepaid energy users have yet to claim a £12 rebate they're due, new figures from the Department of Energy and Climate Change (DECC) reveal. If you're one of them, you've only got until 28 February to do so – here's how.

The Government first announced back in 2013 that electricity customers would be paid a £24 electricity rebate as the result of moves to lower the cost of green levies, with the first £12 paid in the winter of 2014/15 and the second this winter (2015/16).

Energy users with standard meters had the rebate automatically applied to their bills, but those who were prepay customers on 11 October 2015 need to actively claim it.

Now DECC's told MoneySavingExpert that according to its most recent figures, from 22 January, some 1.3 million of the 4.5 million prepay users have yet to claim their credit.

Here's full info on how to do so – see our Cheap Prepaid Gas & Elec guide for more on how to cut your costs on a prepay meter.

How do I claim my £12 prepay credit?

Claiming your credit's simple. Anyone in England, Scotland or Wales who was a domestic prepay electricity customer on 11 October 2015 should have received a letter in November 2015 from their energy supplier with a voucher for the £12 credit. If you still have this somewhere, you can dig it out and take it to any post office to redeem - there the £12 will be automatically transferred to your key or card, which you can use to top up your meter.

If you binned the letter though or don't think you got one but should have, then ring your supplier. They will be able to see that you haven't already redeemed a voucher and will be able to send you a new one. However, this may take a few days to arrive, so do it ASAP.

Here are the telephone numbers for the major suppliers:

British Gas - 0800 048 0202
EDF Energy - 0800 056 7777
E.on - 0333 202 4606
Npower - 0800 073 3000
Scottish Power - 0800 027 0072
SSE - 0800 980 8831
The Co-operative - 0800 093 7511
EBICo - 0800 458 7689
First Utility - 0192 632 0700
Good Energy - 0800 599 9440
Utility Warehouse - 0333 777 0777

Some with smart prepayment meters – which can be topped up remotely – may also have had their meter credited automatically rather than being sent a voucher. If you've not received a letter, and aren't sure whether your meter has been credited automatically, ring your supplier to check.

Prepay energy user? You've four weeks left to claim a free £12 credit
Just four weeks left for 1.3 million prepay energy users to claim free £12 credit

What if I've changed supplier?

If you've changed supplier since 11 October 2015 then it's likely your rebate will come from your old provider, rather than your current one – if you need to chase, that's who you should call. The voucher you receive from your old supplier can still be used to top up the prepay key you have with your new supplier.

What if I'm no longer a prepay customer – can I still get the credit?

If you were previously a prepay customer, but have since switched to a standard meter, you can still get the rebate. It should be applied automatically to your monthly or quarterly electricity bill.

But if you've switched very recently or can't see the deduction on your bill, ring your supplier to check.

I'm on a standard, not a prepay, tariff – how can I check I got the credit?

If you're on a standard tariff your money should have been automatically deducted from your electricity bill in November 2015. If you aren't sure if you got it, check your bill – it should be itemised on it. If you can't see it, ring your supplier.