Businesses have multiple meters for a variety of reasons. It's possible that you're a bigger business so use more energy or perhaps you're in a premise that has changed shape over the years. 

This may mean that you have multiple contracts with different contract end dates, so just keep an eye on it so you don't fall into expensive out of contract rates. If you're with the same supplier for all of the meters, you should only get one electricity bill, so look out for multiple MPANs on there.