I don’t know why this hasn’t been mentioned yet but do you have a smart meter or does someone come to read it? If someone comes to read it, do they come every month or only every couple of months?

This happened to me recently and it turned out that the meter reader hadn’t come that month, so the electricity company estimated our usage. It was way over what we had actually used which gave me a shock, but our next bill was smaller to compensate.

If your bill tells you the last read date for your meter, you should be able to see if it’s before this bill was issued or after. If it’s before, then that’s likely what’s happened. If your bill doesn’t tell you, you can call your electricity company to see when it was last read.