If the form is online it may be a good idea to draft it offline first e.g. In a word processing package like Word and save this on your computer. This way you’ll be able to run a spell check before you copy the info into the online system. It also means you’ll have a back-up if there’s a problem with the form.
Many sites allow you to store your application online which will let you review or edit your application if required. If you need a username or password to access the site it will be very important to record these in a safe place for future reference.
You may be allowed to use one form for multiple job applications. If this is the case you should update relevant parts of the application form to highlight your skills / experience to each specific post.
Online forms can be longer and more complicated than paper forms – follow the instructions carefully and check how many screens you have to fill in before you can submit your application. If necessary, copy all the questions into an offline document – that way there’s no danger of submitting an incomplete application.