Pay your tax on time
You must pay any amount due for 2011-12 by 31 January 2013. The payment deadline is the same whether you sent in a paper or an online tax return.
HMRC recommends that you make your Self Assessment payments electronically. It’s safe and secure and provides certainty about when your payment will reach HMRC.
When you make a payment, be sure to use the right reference number. It’s called a Unique Taxpayer Reference or UTR. For example 1234567890K. Don’t forget the ‘K’ at the end.
If you’re worried that you are unable to make the payment on time you could contact the Business Payment Support Service on 0845 302 1435 for assistance. Please note: this service is for taxpayers who are aware that they maybe unable to pay the payment due in full before the payment deadline.