Your sample customer starts a 30-day period on a $49 monthly plan. With 15 days remaining, they upgrade to a $99 plan. This example credits the unused old-plan time and charges the same remaining days at the new price.
Show the adjustment separately
- Original period charge: $49.00.
- Unused old plan: $49 × 15 / 30 = $24.50 credit.
- Remaining new plan: $99 × 15 / 30 = $49.50 charge.
- Upgrade adjustment: $49.50 − $24.50 = $25.00.
- Full-period total after the adjustment: $49.00 + $25.00 = $74.00.
If the original $49 was already paid, the incremental amount is $25. The $74 sample draft explains the full period; it is not an instruction to collect $74 again.
Open the upgrade sample. Change the prices or remaining days, then generate the sample draft.
Decide the rules before changing a subscription
This illustration uses daily proration with the supplied period length and rounds each adjustment line half up to cents. Production rules may instead use timestamps or provider-specific proration. State your effective change time, timezone, rounding policy, and whether an adjustment is collected immediately or on the next invoice.
Test an upgrade at the beginning, middle, and end of a period. Review the existing payment and credit balances so the customer is not charged twice. The browser sample does not modify a real subscription or collect a payment.
Review the proration guide, then create a free beta workspace to validate your configured workflow with test data.