Microsoft 365 trial ending, moving to paid without losing anything

one exception: if you started the trial through the App Store or Google Play rather than Microsoft directly, the billing and plan are managed in that store's subscriptions, not your Microsoft account. that's where to check or switch plans.

Nothing to reinstall. The trial is already a subscription on your Microsoft account, it just hasn't charged yet. Unless you turned off recurring billing it rolls into the paid plan on its own on the renewal date. Worth logging into your Microsoft account and checking Services & subscriptions before next week, so you know which plan it will become. Family and Personal are priced differently and it's easy to have picked the wrong one at signup. Your files, OneDrive and installed apps all stay exactly as they are.