Can I transfer my mobile number to a pay as you go SIM?

I think you can but you would need to clarify with company you are currently with. When i had a pay as you go with O2, i wanted to take my number with me when i switched to 3. O2 tried everything to get me to stick with them but i wasnt getting a good an offer as i would then get with 3, they agreed i could transfer my number across. It took a couple of days but they did let me take it with me. It is a number i have now had for about 8 years.

Yes you can in most cases. However, do check that if you are currently on monthly contract that this contract terminates before switching to a SIM unless you want to incur heavy charges. As for the the best SIM deal look no further than Tesco SIM deal. I am about to join it in the next 24 hours as my contract finishes today.If you are a Tesco Clubcard member you also get triple Clubcard Points.