You can change your plan in your Steady account at any time. How many choices you have depends on how many plans the publication you support currently offers.
The short version:
Upgrades – to a more expensive plan, or from a monthly to an annual plan – take effect immediately; the amount you have already paid is offset pro rata against the new price.
Downgrades – to a cheaper plan, or from an annual to a monthly plan – take effect at the end of your current plan period.
All details, example calculations and special cases (guest memberships, error messages, accidental purchases) are covered in our main article: