# Subscription-Prorate Settle the price difference immediately when you change `amount`, `interval` or `intervalCount` mid-period. Unused time is credited at the current price. An `amount` change charges the remaining time at the new price and keeps the billing period. An `interval` or `intervalCount` change charges the full new price and restarts the period from now. A positive difference is charged to the saved payment method. A negative difference is refunded against the payment that funded the current period, up to the amount that payment received. Only one prorated change is allowed per billing period. Accepted on active and trialing subscriptions only. On a trialing subscription the fields change and no money moves, because there is no paid time to credit. Any other status is rejected. You cannot combine `prorate` with `nextPaymentAt`, `trialPeriodEnd`, `cancelAtPeriodEnd`, `pauseAtPeriodEnd`, `pauseIntervalCount` or `skipIntervalCount`. **boolean**Subscription-Prorate Settle the price difference immediately when you change `amount`, `interval` or `intervalCount` mid-period. Unused time is credited at the current price. An `amount` change charges the remaining time at the new price and keeps the billing period. An `interval` or `intervalCount` change charges the full new price and restarts the period from now. A positive difference is charged to the saved payment method. A negative difference is refunded against the payment that funded the current period, up to the amount that payment received. Only one prorated change is allowed per billing period. Accepted on active and trialing subscriptions only. On a trialing subscription the fields change and no money moves, because there is no paid time to credit. Any other status is rejected. You cannot combine `prorate` with `nextPaymentAt`, `trialPeriodEnd`, `cancelAtPeriodEnd`, `pauseAtPeriodEnd`, `pauseIntervalCount` or `skipIntervalCount`. **Example: **`false` Subscription-Prorate ``` false ```