Self Assessment filing

I noticed there is a self assessment filing i have already completed mines back in may but realised it might be wrong so i have been inputting everything into quickfiles to check if i made mistakes it appears i was just about correct.

But i am wondering what the filing in quickfiles does and it talking about accountants reviewing it, if that free service how is it paid for?

It’s probably best explained here:

http://help.quickfile.co.uk/main/1/accounts_service__self_employed_.htm

The latest pricing is here:

http://www.quickfile.co.uk/resources/pricing.aspx