We've blogged previously as to why you should always take a meter reading yourself when moving house.
However what should you do if you have left your house and haven't taken a meter reading. What should you do?
Scenario 1 - It's only been a few days but you can't get back to read the meter. Solution: You can get a friend/landlord/real estate agent to read the meter and give you the reading. You can then give this reading to the electricity company.
Scenario 2 - It's been a long time and now the Power Company are calling you due to your overdue account.
At this stage you could lie and make up a reading. Don't do this, it's generally obvious what is happening and the Power Company will refuse to believe you.
If there has has been a meter reading after you moved out ask to use that reading to close the account. This means you may have to pay some money but hopefully not so much.
Scenario 3 - You had an advanced meter. Little known fact - AMS (the company that monitors the advanced meters) takes a reading from every meter every day. Insist that they use this reading. If the person you are talking to tells you that you are wrong, talk with a manager. Do no let up until they locate this reading.
Scenario 4 - You posted in the the reading / submitted it online. We would recommend just not giving in, blame the Power Company, insist they wipe any liability from your last invoice and if the person refuses to budge make a complain.
Hopefully that covers the obvious scenarios, if you think of any more just let us know and we'll try to help.