When you switch suppliers, your new supplier will ask you for meter readings. The first thing that must happen is they are sent for validation. This is a standard industry process to check that your readings are (roughly) inline with what the energy industry expects. Once these checks have been done, your readings are sent to your previous supplier, so you only need to give readings to your new supplier.

The whole process normally takes 2-6 weeks from when you send your readings until your previous supplier gets them.

Gas and electricity readings are validated by different companies, so it’s normal for your previous supplier to get these at different times.

That's all you really need to know. If you would like to know more about the validation process, read on for more detail.

### The validation process

An estimated reading is calculated from your last known reading and counting on by how much energy they expect your meter to have used since then.

The added Estimated Usage is calculated specific to your meter using your meter's estimated annual usage, which is calculated and managed in a centralised industry database using historic usage data. See our help page How are my charges calculated? for more information about your estimated usage.

When the validation company compares your reading against their own estimate, they check if your reading is within certain bounds around their own estimate.

• The lower bound is the last meter reading taken. Your meter should never run backwards, so your opening reading should never be lower than a previous reading.
• The upper bound is calculated as the reading if you used 2.5x the Estimated Usage expected.

#### Example

A customer gave a reading to their energy company on 1st October 2016 of 32,536. They switch to So Energy, and their supply start date is 1st December.

The validation company expects that from 1st October and 1st December this meter will use 333 kWh. This means that the upper bound would be 32,536 + 2.5 x 333 = 33,369 lower bound = 32,536. When we receive an opening reading, if it is between 32,536 and 33,369 it will be validated. If it's outside of these then it will fail and we'll use the estimate of 32,536 + 333 = 32,869.

Once the validation process has been completed the opening reading that is being used is sent over to your previous supplier so they can use it to produce your final bill with them.

### I have provided an opening reading, why didn't you use it?

If the reading you have given is outside the reading 'bounds' it will fail validation and won't be used. That's not to say it isn't correct. The usual reason for this is that your previous supplier may not have had a recent reading from you.

If you would like to use your reading rather than an estimate, it is possible to dispute the estimated reading used for you. Any final bill which may have already been generated will need to be changed if a new reading is agreed (See My opening reading is wrong for more details).

#### If the opening reading provided is too high

Following on from the example above, if we received an opening reading of 34,000 it would fail validation because its greater than the upper bound (33,369). A reading of 32,869 would then be used to open their account.

#### If the opening reading is too low

If we received an opening reading of 32,300 it would also fail validation because it's lower than the previous reading (lower bound 32,536). A reading of 32,869 would then be used to open the account.