If you have submitted an application for a job which has not yet closed and  at a later date realise there's a mistake or there's something you would like to add, don't worry.

Simply find the job advert and reapply for the job. 

When the new application is created, click "Reuse previous application" (if this was the last application) the same details should pull through but you can overwrite the incorrect details or add anything you would like.

When you submit your corrected application this will replace your previously submitted version.