Getting to know your electricity top up meter

This article contains helpful information about your electricity top up meter. Use the contents below to jump to a specific section, or take a read through to get a better understanding of all things prepay.

Getting started

Topping up

Reading your meter

Error messages


Emergency credit

Managing debt

Lost your key

Moving home

Additional support

Power cut 

Getting started

Before you use your new key for the first time, there are a few things worth knowing:

  • Don’t use your new key before your switch has completed. We'll email you to let you know when you've switched.
  • Credit on the meter will be wiped when you use your Bulb key for the first time. So wait until your credit is close to zero before using your new key
  • Before topping up, put your key into your meter for 60 seconds. After a minute has passed, your key will be connected and ready to top up

Top up at your nearest Paypoint or Payzone

Once you’ve set up your key, you’re ready to top up. Find your nearest Paypoint or Payzone.

  • After you've topped up, insert your key into the meter and wait 5 seconds. This will transfer the credit from you key to the meter. 
  • When you’ve finished topping up, take your key out of the meter. This will preserve the meter’s battery life.
  • You should always keep your meter topped up. When you’re away and not using electricity, you will still need to pay for the daily standing charge.

Press the blue button to read your meter

A top-up electricity meter with a blue button on the top right.

This is your meter. When it's low on credit it will turn off to save power. If this happens, pressing the blue button will wake it up, and screen 'A' will show how much credit you have left.

The left hand side of the screen will show you which screen you're on. And the slot under the blue button is where you insert your key.

If you’re not sure how to read your meter, we have a helpful article on how to read different kinds of prepay meters.

What the error messages mean

There’s a few reasons your meter might be showing an error. In the table below we’ve made clear what the most common errors mean. If you can’t see your error, check out our full list of prepayment meter errors.

What the error means

What causes this?

What should I do?

Error D2
Your key is blank

Your key wasn’t programmed properly before being sent.

Get in touch, we’ll give you a code to get your key working with your meter.

Error D4
Your meter serial number is different to the one on our records.

Your key has been programmed to work with a different meter.

Get in touch, and let us know the correct serial number on your meter.  We’ll create a code to get your key working again.

Error D6
Your key wasn’t programmed correctly before it was sent. 

This error can pop up when a new key isn’t talking to your prepayment meter correctly

Get in touch, we’ll get an appointment booked in for an engineer to come and replace the battery.

Top up payments cover your energy and your daily standing charge

A standing charge is a daily fee which covers costs like engineer visits, meter maintenance and the cost of keeping you connected to the network. You need to pay your standing charge even if you're away from home. This is why it’s important to always keep your meter topped up.

The daily standing charge is 26.56p for a top up electricity meter.

Use your emergency credit when you can't top up

If this happens and you’re unable to top up, you can use your emergency credit. 

Emergency credit on an electricity meter is normally £5. If you use it, you’ll need to pay it back when you next top up. 

After using the emergency credit, your next top up will need to cover the amount of credit you used and the daily standing charge.

For example, if you’ve used £4 emergency credit over 7 days, and the daily standing charge is 26.56p, you’ll owe £5.86. So if you next top up £10, you’ll have £4.14 towards your energy.

£4 emergency credit
£1.86 standing charge (7 days x 30.42p) 

£5.86 owed

Read how to activate your emergency credit.

Managing your debt

Debt can be built up by a daily standing charge when a meter has no credit. This can happen when the property is empty for an extended period of time. A member may also be in debt if they’ve switched from a credit meter to a prepay meter to help manage payments.

You can read more about the different types of charges here.

If you've built up debt, get in touch so we can set up a weekly repayment plan. This means you’ll make weekly payments, through your top ups, until your balance is paid off.

We’ll take your first payment on the first Wednesday after you've set up your repayment plan. If you don’t have enough credit at the time, we’ll take it when you next top up.

Get help managing your debt

If you’re struggling to pay for your energy, there are ways to get help:

  • If you’d like to change your repayment amount, call us on 0300 30 30 635. We’re open Monday to Friday, 9am to 5pm
  • StepChange is a charity that will help you create and manage a budget if you’re struggling to make payments. Call them on 0800 138 1111 or visit

Contact us if you’ve lost your key

Get in touch to request a new key. It will arrive within 3 to 5 working days. If you're running low on credit, you can use your emergency credit until your new key arrives.

Let us know when you’re moving home

Moving out

When moving out of your home, you need to let us know so we can stop charging you for the energy at that property. Just let us know by email or over the phone. We'll ask a few questions and do the rest ourselves.

When you move out of a property you don’t have to do anything with your card, we recommend leaving it by the meter for the next person moving in.

Moving in

If you’ve just moved in to a property supplied by Bulb, head to our Moving in page to create an account.

Getting additional support

We offer free support services if you, or someone you live with, needs help to manage your energy supply. For example because you have restricted mobility or a learning disability.

Some of the support services we offer include:

  • helping with meter readings
  • providing statements in an accessible format
  • quickly reconnecting your home’s energy supply if it goes out

You can apply for additional services by filling out our extra services form.

Call 105 if you’ve had a power cut

If you're experiencing a power cut, you should contact your Distribution Network Operator (DNO). Their number is 105 and free of charge.

Get in touch if you need more help

You can send us an email at any time, or get in touch by phone or our live chat service Monday to Friday, 9am to 5pm.

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