You cannot accept your offer and pay at a later date.

A Confirmation of Enrolment (CoE) will only be issued after your first payment (as listed on your offer letter or on the online acceptance portal) is made. 

You are advised to make the payment as outlined on your letter of offer as early as possible to allow sufficient time, to apply for your student visa. 

The UWA undergraduate degree portion of your fees is payable once your pathway course is complete, and entry requirements to the degree program have been met.