Get your pen and paper or camera phone at the ready.

Gas and electric bills are set to rise by more than 50% from tomorrow (Friday) when the energy price cap increase comes into force, permitting companies to charge more for the gas and electricity that you use and a move which is likely to see the cost of the average bill leap by about £600 a year.

But before higher energy prices kick in, households are being urged to take a good look at their gas and electricity meters and take down an accurate reading, in order to have an up-to-date record of the energy their home has used prior to the impending rise and send it to their supplier to make sure they are not charged the higher rate for any energy they have actually used this month under the lower charges.

This meter reading, say experts, should be done today (Thursday) – which is being coined National Meter Reading Day.

From tomorrow (April 1), alongside an increase in standing charges, which is the fixed daily line-rental like charge that you pay to have your supply regardless of the amounts you use, many bill payers are likely to find that they soon will also be paying more for every unit of gas and electricity they consume.

Money Saving Expert's Martin Lewis has described the process of submitting a meter reading on the last day of the month as 'drawing a line' under the current pricing arrangement before the hike comes into force the very next day.

He added: "Diarise to do a meter reading on March 31, so you draw a line and tell the energy company all this energy I've used should be at the cheap rate."

How to submit a meter reading

Suppliers need regular readings from meters to work out the price of your bills. If you don't send them readings, says Citizens Advice, companies will instead estimate your usage which means your bill might end up being too high or low subsequently, leaving you owing more.

Most customers, using online accounts, can submit meter readings through their supplier's website or via the company's app if they use it. Some energy firms may also offer live chat services through their website with an advisor who can take the details or you can perhaps reach them by phone to update your usage records.

But given the price cap increase tomorrow (April 1) and the concern over rising energy bills - there could be a lot of people trying to enter their meter readings today and so the advice is to try and avoid holding on the telephone line if you can and free that capacity up for homes or older people who may benefit from further support.

For anyone struggling to read their meter - and who can't get through for further help - Citizens Advice shares a guide on its website to help people understand exactly what it is they need to do. You can follow that here.

If you have a smart reader

If your home uses a smart reader you will know that it regularly sends energy use updates to your supplier. However these are normally regularly scheduled for the same date or time each month and so there is no guarantee that it will automatically update your usage today (March 31).

Should you wish to send a further updated reading, so that you have a concrete record of what you've used by March 31, there should be nothing to stop you doing so and you'll need to enter the figures via your online account or via the app as you would ordinarily.