Many TPD policies offer 'guaranteed insurability' or 'future insurability' options that allow you to increase your sum insured at specific life events without new medical underwriting. Common qualifying events include marriage, divorce, the birth or adoption of a child, taking out a new mortgage or significantly increasing an existing one, salary increases above a defined threshold (commonly 10–15% year-on-year), starting a business, and the policy anniversary itself. Each policy specifies the maximum increase available per event (typically a percentage of your existing cover, with an absolute dollar cap) and the application window after the event (commonly 30–60 days). Many policies also include automatic indexation — your sum insured rises each year in line with the Consumer Price Index (CPI) without you having to do anything, ensuring purchasing power keeps pace with inflation. The premium rises proportionally to the new sum insured. There are limits: total cover cannot exceed the insurer's maximum, you must still be working and not currently on a TPD claim, and the option may be available a finite number of times. Health-related deteriorations after the policy started cannot be excluded from increases under guaranteed insurability — that is the whole point of the option. If you want to increase cover outside the qualifying events or beyond the option limit, you will need full underwriting.