CT600 on line how to submit previously saved file

I have completed HMRC's on line CT600 and accounts but not filed them as I needed the client's confirmation first. The file is saved on my PC under the client's name.  

Now I have the ok I cannot see how to bring  the acrobat file back on line and submit it. Self assesment info is automatically saved so you can go back into it before submission but I can see no method of 'reactivating' a previously saved acrobat file for a company.

Do I have to go through the whole input procedure again?