Change plans any time from Settings → Billing. Upgrades, downgrades, and switching between monthly and annual all prorate in place: no checkout redo, no double billing.
Canceling? The flow offers alternatives that might fit better:
Switch to annual for the lower rate.
Downgrade one tier.
A one-time 50%-off month.
Pause for a month: billing stops and dashboard access pauses too. You can resume early.
If you cancel outright, your plan runs to the end of the paid period.