Can anyone help me here.

My father (professional builder) and I removed a suporting wall (chimney) about 4 years ago from the end of our house, and inserted a steel H beam 9ft 10" x 1ft(to hold the weight of the wall above).

Problem is i did not get planning pemission for this, can anyone tell me what i need to do, to get a certificate or whatever is needed as i want to sell my house.

I don't think it's planning permission you need as internal works are largely exempt (unless the buidling is listed).

Building regulation approval is the thing you're looking for - I think you can apply for what is known as a 'regularisation certificate' for work carried out more than 12 months ago but after 1985...

Certificate is issued by the Building Regs Dept of your Local Authority - do a google search on 'Building Regulations Retrospective approval' and you'll find out more about what you need to do.