Tax Office reference - Online Application

Dear all,
Your advice on the below would be much appreciated.

I am in the process of completing an online application for British Citizenship.
I have question in regards to the tax office reference number that is requested by the Home office.
Is this the UTR number of the company or the employers Paye reference number.
Please note I am a director and an employe of my own limited company.

Many thanks in advance!

If you classify yourself as employee use the company PAYE reference, if self-employed use the UTR reference.