It's a horrible feeling when you open your gas and electricity bill and find that it's much higher than you expected.

Don't just shrug and accept a high bill though - it's important to find out why your gas and/or electricity bill has gone up.

Use our 'Why has my gas and/or electricity bill gone up?' checklist below to work out why, and find out what you can do to cut your bill back down to size.

1. Is it an estimated bill?

If you receive a bill that's higher (or lower!) than expected, your first port of call should always be to check whether or not it's based on an estimated meter reading.

Estimated meter readings can get your usage completely wrong. You can find out whether or not it's an estimate on your bill - it will have 'estimate' or an 'e' written next to the number of units you've used.

If it is an estimate, take your own meter reading and give it to your energy supplier - they'll send you a new, correct bill.

2. Has anything changed since your last bill?

If you've checked that the meter reading on your bill is correct, think about whether or not anything has changed in your home since your last bill. Has the weather been unusually cold? Have you been spending more time at home or are your children at home more because of the school holidays?

Have you bought any new appliances? These things might sound trivial, but they can have an impact on your bill.  An energy monitor can help you to work out which appliances are using the most electricity in your home.

3. Has your fixed price plan ended?

Over the last five years or so, many people have signed up for fixed price energy plans to protect themselves against rising prices.  If you've suddenly noticed a sharp increase in your bill, it could be because your fixed price plan has come to an end.  

If this is the case, then it is definitely time to do a comparison and switch to the cheapest deal for you, to offset some of the increase to your bill.  

Find out more about what to do when your fixed price plan ends .

4. Have your discounts ended?

Another possible explanation for a high energy bill is that an introductory discount you were receiving has ended.  If this has happened to you, then it's a good idea to see if there's a cheaper deal available.

Compare gas and electricity prices to find out which supplier is the cheapest - you may be surprised by the result.

5. If the bill is correct and you're already on the cheapest plan for you...

If you're sure your bill is correct and you know that you're already on the cheapest plan for you, don't panic, there is still help available to you.

 You can cut your bills by using less energy and being more energy efficient - take a look at our energy efficiency tips and these energy saving gadgets .  You can also get in touch with the Energy Saving Trust for more help and advice. If you're worried about how you're going to pay your bill, speak to your energy supplier.  They can arrange a repayment plan so you can pay your bill gradually.  Read our article on energy debt to find out more.