I think OP just means the 5 yr interest only period is up in August, the tracker rate will continue but as mentioned with full capital and interest repayments.
I know there was a facility at one stage recently to request a further 2 yrs interest only on investment mortgages, you might ask the adviser is this still the case. It was granted once requested in writing prior to the expiration of the 5 yr term, it may have been dependent on there being at least 15 yrs left to run on the mortgage when int only finished.