If i want to work as a contractor in the UK, would i need to calculate and pay taxes myself?

Right now i'm working in a permanent position, but I know for a fact that Contractors doing the same job gets paid significently more.
If i do want to go into contracting, will I need to hire an accountant to do my book keeping? With Income Tax a,d National Insurance and all their complexities involved.

The straight, short, simple answer is 'of course you will'.....unless you wish to do it for yourself.

Simply... yes.

If you are from abroad and not familiar with the UK tax system, then you should get an accountant - mistakes with tax can be very expensive!

You'll need to fill in a tax return.
You can do this online nowadays.
If you're new to this I'd certainly hire an accountant.

You don't NEED an accountant IF you can do it yourself. The trouble is that if you get it wrong you really are in trouble. The inland revenue and VAT people don't take excuses too easily.

Of course Income Tax & NI will have to be calculated & paid depending on your income. If you call your self a contractor/sub contactor but you are working for the same company all the time, then you must be an empoyee paid on the terms of PAYE, as you are not self employed, seeking , advertising & enterprising future work for your self or your company.