Some of the responses here are funny! Just go ahead and move it using an electrician, nothing will happen. Much as "the authorities" would have you believe, there's no such thing as the electricity police!
First - The meter is owned by the electricity distributor, who are NOT the company you pay your bills to! They are the electricity provider. Since this split, these two parties rarely communicate.
This was the advice I had when I did this. The guy that reads the meter works for the provider, and will probably not give a care about the distributor's property having been moved. Likewise, the distributor (who owns the meter) won't give a care about what the meter reading says.
I've done this in 2005 by getting an electrician to do it, and it cost me £120. In order to do it, the electrician had to break one of the seals on the meter, and said for me to call the elec provider and inform them about the seal, and say that an electrician had to remove and test for safety reasons. He said for me to show them his invoice and it would all be fine. And it was. In fact, no-one cared at all. So - Everyone was happy. Had the meter read several times since with no problems.
Done it in the last two years.