@PCJM40,
What I would do is start my "shopping around" 2 months before my contract is due to expire and whittle down the list of supplier to, at most. 4 providers. Then at the beginning of the last month I would contact my current provider and see if they could max the price of the cheapest provider that I found. This gives you the option of either staying with your current provider, if you're completely happy with them and they can match the cheaper price, or cutting bait and switching without incurring any extra fees.
HTH,