Hi, anyone got experience of doing this as Im getting two different answers from the IR 
My SA for 06-07 said I had an additional tax liability of £20k to pay which I did, this meant that for 07-08 I needed to make two payments on account of £10k, the first payment on account for 07-08 was made 31 Jan 2008.
Now I know now my true tax liability in my SA for 07-08 is actually £15k fine I thought I will just reduce my second payment on account to £5k as I've already paid the £10k. However the IR system means you have to reduce both payments you cant do 1, so I have to reduce both payments to £7.5k which means I over paid in Jan on the first payment by £2.5k. One person at the IR has told me that this £2.5k would be avaliable to use against my 08-09 return, or they can refunded it, but another chap there said it will be seen as a credit on my account so I just have to pay the £5k outstanding balance. Confused

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