I think you can only have one ISA a year in your name but not sure about this. The maximum for this 5th April 2013 is I think £5,760, so maybe you can put half in one ISA and half in another, but why would you want to do this? I would just find the best cash rate for another year and transfer it. If you want to transfer the whole amount at the beginning of the new ISA year, don't take the money out and put it in your bank, it has to be transferred from your original IsA provider to the new ISA provider - otherwise you will lose all the interest you have made over the years. You can withdraw the whole lot to invest in other things, and take all your interest out as well, but if its to go in another ISA, as I say above, the original ISA provider has to transfer it. Hope this makes sense! Phone your ISA provider for more information as I'm not sure about splitting the ISA.