Pay HMRC early or try and earn interest?

[Zorra]

I owe HMRC £20,000 total for 2013-14 and 2014-15 tax years as I'm self employed. I have to pay £15,000 by January 2015 (13-14 was my first year so it has to be paid upfront) and I have got the money put away. So my (possibly daft) question is, should I just pay it now, or try and find a home for 6 months and try and earn some interest on it? I will need to spend it in January at the latest so I'll need to access it, and I'll need to make sure I don't accidentally spend it on anything else... I am veering towards just paying it but I don't want to miss out! Thanks for the ideas!

HMRC does not pay interest to individuals when tax liability is paid early. They may pay a small repayment supplement if you overpay tax and there's a delay in issuing a refund. Therefore I would put the money into savings until January. You should get a few pounds of interest - rather it goes in your pocket than HMRC's.

Interest rates won't be high but it's better than nothing, so keep hold of it for now.

I'd put it into a Cash ISA as soon as the allowance goes up and earn some tax free interest between now and 29th January when you have to hand it over to the little darlings

BUT
If your tax bill is that high, have you looked at going limited ?

You can get 1.5% on a cash isa instant access so that would be £150 a year, you'd get about £75 between now and January. Do you want to give that as a gift to HMRC? Pay it in the last week of January like everyone else, just don't forget!

sorry a bit more than that, I was using 1% not 1.5

I buy premium bonds with mine

I'm getting 2.2% on my isa
even better rates of return come from temporarily overpaying mortgages (mine works out at 3.6% tax free)

Thanks everyone, sage advice!

Talk - I can't, my clients won't hire me as an 'organisation', only as an individual. It's very annoying as I feel like I pay oodles of tax :( Ah well.