> For the complete documentation index, see [llms.txt](https://developer.paddle.com/llms.txt).

# Upgrade or downgrade a subscription billing frequency without billing

Specify Paddle shouldn't prorate or bill for changes when changing a subscription billing frequency, like when customers upgrade to an annual plan from a monthly plan.

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## What's new?

We updated the Paddle platform so that now you can use `do_not_bill` as the proration billing mode when changing billing frequency for a subscription.

- **proration_billing_mode** (string): How Paddle should handle proration calculation for changes made to a subscription or its items. Required when making changes that impact billing.

There are no changes to endpoints or fields in the API as a result of this change — it's an update to the allowed values you can use when changing billing frequency for a subscription.

## How it works

One way that customers might [upgrade or downgrade their subscription](https://developer.paddle.com/build/subscriptions/replace-products-prices-upgrade-downgrade.md) is by changing their billing frequency. For example, a customer who pays monthly might say that they'd like to "upgrade to the annual plan." To make this change in Paddle, you replace prices that bill monthly with prices that bill annually.

When replacing items on a subscription with different billing intervals, you must include the [`proration_billing_mode`](https://developer.paddle.com/concepts/subscriptions/proration.md) field to tell Paddle how to bill for the replaced items. Previously, the only accepted allowed values in requests like this were `prorated_immediately` and `full_immediately`.

We updated the Paddle platform so that now `do_not_bill` is now an accepted allowed value for `proration_billing_mode`. When you use `do_not_bill`, Paddle doesn't calculate proration or bill for the changes made to the subscription. This means you can upgrade or downgrade a subscription billing frequency without charging customers.

`do_not_bill` was already a valid allowed value for `proration_billing_mode` in request bodies when making other changes to subscriptions, so there's no change to the API as a result of this change.

## Next steps

This change is available now. You don't need to do anything to get this change.

There are no changes to endpoints or fields in the API as a result of this change — it's an update to the allowed values you can use when changing billing frequency for a subscription.

You can [upgrade or downgrade the billing frequency for a subscription](https://developer.paddle.com/build/subscriptions/replace-products-prices-upgrade-downgrade.md) using the API.
## Summary of changes

| Name | Type | Change | Entity | Description |
| --- | --- | --- | --- | --- |
| `do_not_bill` | Enum value | added | proration_billing_mode | Required when changing billing frequency to items with different billing intervals. |