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Energy back billing

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What is energy back billing?

If you haven’t been charged correctly for energy that you used in the past your supplier can send a catch-up bill. This is known as back billing.

Note this only applies if the supplier has not billed correctly. If you have an old unpaid energy bill, that does not count as back billing.

Can energy suppliers back bill?

Yes, but only for energy used within the last 12 months if they haven’t sent an accurate bill before then.

What are the rules on catch up bills?

This “back billing principle” was introduced by Ofgem in May 2018. They decided it was unfair for a supplier to charge for energy billed incorrectly over 12 months ago. Suppliers also have to include back billing rules in their T&Cs.

These rules apply to all payment methods, so whether you pay by direct debit or on a prepay meter your supplier can’t raise a new bill for energy used over 12 months ago.

If a supplier has undercharged you, they can still send a bill for up to 12 months after the energy was used.

How far back can an electricity bill go?

If you have been billed correctly then a supplier can chase you for outstanding payments, no matter how old they are. However, if you have been charged incorrectly your supplier can only send a catch-up bill for the last 12 months.

Why would you be charged for old usage?

Possible reasons for back billing are:

  • Payments have been based on estimated energy usage that was too low
  • Incorrect contact details meant that bills were not delivered

Occasionally back billing also occurs because:

  • The supplier has been charging for the wrong meter, which had lower usage than yours
  • A direct debit was accidentally cancelled so payments were not being made as expected

How can I check a back bill is correct?

If you have been paying estimated bills the supplier can charge you the difference between actual and estimated usage in the last 12 months. To check this bill is correct, first look up your estimated monthly usage in your energy account. Then calculate your actual monthly usage from your meter readings. Your back bill should be no more than 12 x (actual monthly usage - estimated monthly usage) x unit rate.

If you have not received an energy bill, then your supplier can charge you for any energy used but not billed within the last 12 months. You should not be charged more than 12 times your typical monthly bill.

If you have been charged for the wrong meter and your true usage was higher than the meter you were charged for, then you can be charged for the difference in usage between the 2 meters for up to 12 months. Your back bill should be no more than 12 x (actual monthly usage on your meter - monthly usage of the meter billed) x unit rate.

If your direct debit was accidentally cancelled the back bill shouldn’t be more than 12 times the amount of the direct debit.

When do back billing rules not apply?

If a customer purposefully causes a supplier to send incorrect bills then they can be charged for the energy missed, no matter how long ago it was used.

For example, customers are not protected if they have taken actions to prevent payments such as:

What’s the difference between back billing and debt repayment?

Back billing only applies in cases where the energy supplier has not charged accurately. If you have received correct bills throughout, your supplier can still chase you for a payment on usage that is over 12 months old.

If you do have outstanding debts of more than 12 months, your supplier should organise a payment plan so that the outstanding amount can be paid in manageable increments. You are not required to clear this debt within 12 months, but it also won’t disappear if you don’t pay it in that time frame.

How to avoid catch up bills

The most common cause of energy back billing is a supplier using estimated bills instead of charging for actual usage. If this is the case it will be indicated on your bill, and can be avoided by submitting a new meter reading every month. When you submit the meter reading you can ask the supplier to generate a new bill based on actual usage. You do not have to pay based on estimated usage.

It’s also important to make sure you’re receiving your bills on schedule. Most households will be billed monthly, but some will be billed every 3 months. Check with your supplier when your statements should come through and chase your supplier if they haven’t been received.

What should I do if I haven’t been billed for over a year?

If you haven’t been receiving bills:

  1. Chase your supplier to send you a statement. Do this on email so there is a record, and it’s clear you’re not avoiding payment.
  2. When your supplier does send you a bill, make sure they are not charging for more than 12 months old usage.
  3. If a supplier tries to charge for more than 12 months dispute the amount. You are protected by Ofgem's rules.

If you aren’t sure who your supplier is, read our guide to find out.

How do I dispute an energy bill?

If you think you are being billed unfairly, first complain to your supplier. It’s best to do this by email so there is a record of the complaint. You can find a template for back billing complaints here.

If your supplier doesn't resolve the complaint in 8 weeks this counts as a “deadlock”, and can be escalated to the Energy Ombudsman. You can find more detail on how to complain to the ombudsman here.

What to do if you can’t pay a catch up bill

If you’ve received a back bill that you will struggle to pay the first step is to contact your supplier. They should be able to agree a payment plan with you. It’s also worth asking if there are any discounts that you are eligible for, or if they have a cheaper deal that you can move to.

If you’re still struggling following contact with your supplier the Citizen’s Advice consumer helpline can offer further support.

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