I'm a slightly-less-than-average energy user, currently paying £180 per month. I used to not worry too much about the amount of credit built up over summer, as my bills were never more than £100 a month and it wouldn't have been a problem to increase payments a bit if I went into debit. However, with the current prices I don't want to suddenly face a big bill in the winter. I'm £300 in credit at the moment. Does that sound like a sensible amount for early August, or shall I ask for a bit back / reduce payments by £20 or so?