Anyone or any company, limited or not that works in the construction industry and works for another construction contractor in the construction industry will get 20% or 30% stopped at source unless you register for Gross payment and then you have meet a criteria like D Skelton states.
That as be the normal process for a few years now and going limited saves you any NI you are liable for.
Iv'e been limited for years and still have a personal UTR so can work as a sole trader or as a paye through my limited company.
Best to have the 2 options at hand, directors and their limited companies have to submit real time submissions to the HMRC now, so you take a wage and at the end of the year get paid in company Dividends.
With offsetting any CIS deductions suffered against your Corporation Tax bill you have to put it in writing to HMRC because the Corporation department don't ask the CIS department. Otherwise you just wait for a rebate but still have to pay the Corporation Tax bill in the mean time.
Its all simple and straight forward and things self employed/ limited people should know.