Prorations

Manage prorations for modified subscriptions.

The most complex aspect of changing existing subscriptions are prorations, where the customer is charged a percentage of a subscription’s cost to reflect partial use. This page explains how prorations work with subscriptions and how to manage prorations for your customers.

How prorations work

For example, upgrading or downgrading a subscription can result in prorated charges. If a customer upgrades from a 10 USD monthly plan to a 20 USD option, they’re charged prorated amounts for the time spent on each option. Assuming the change occurred halfway through the billing period, the customer is billed an additional 5 USD: -5 USD for unused time on the initial price, and 10 USD for the remaining time on the new price.

Proration ensures that customers are billed accurately, but a proration can result in different payment amounts than you might expect. Negative prorations aren’t automatically refunded and positive prorations aren’t immediately billed, although you can do both manually.

You can preview a proration to view the amount before applying the changes. To learn more about how credit prorations work, read our guide.

Prorations and discounts

All invoice items that are prorations (prorations=true) are set to discountable=false. Discounts applied to an invoice containing prorations are only applied to invoice items and invoice line items that aren’t prorations. Any discounts previously applied to the subscription and affecting the amount of the proration are reflected in the proration invoice item’s amount.

Non-prorations show discount adjustments in discount_amounts.

What triggers prorations

By default, the following scenarios result in a proration:

Update	Description
Changing items	Adding a new item or removing an existing item
Changing price	Changing to a price with a different base cost or billing period
Changing quantity	Increasing or decreasing the quantity on a subscription item
Adding trial_end or trial_from_plan	Adding a trial period to an active subscription
Changing billing_cycle_anchor	Resetting the billing period to a new date
Setting cancel_at	Canceling a subscription mid-period (not at period end)

What doesn’t trigger prorations

Many subscription updates don’t affect billing or generate prorations. Make these updates at any time without creating proration invoice items:

Parameter	Description
Configuration and settings updates
automatic_tax	Enable or disable automatic tax calculation
default_payment_method	Change the default payment method
default_source	Change the default payment source
payment_behavior	Control payment attempt behavior
collection_method	Change between charge automatically and send invoice
days_until_due	Update payment due date for send invoice subscriptions
tax_filing_currency	Change the tax filing currency
retry_settings	Modify retry behavior for failed payments
trial_settings	Update trial end behavior settings
pay_immediately	Control immediate payment behavior
pending_invoice_item_interval	Change how often pending items are invoiced
pause_collection	Pause or resume payment collection
proration_date	Set a specific proration date (doesn’t create prorations by itself)
Metadata and descriptive fields
metadata and items.metadata	Update metadata on the subscription/subscription items
cancellation_details	Add cancellation feedback and comments
Updates that act as settings for future non-proration billing changes
discounts and items.discounts	Add or update discounts (applies to future invoices)
billing_thresholds and items.billing_thresholds	Update billing thresholds on subscription/subscription items
cancel_at_period_end	Cancel at the current period end without proration
add_invoice_items	Add one-time charges to the next invoice

Note

These updates don’t generate proration invoice items with proration_behavior=create_prorations or generate invoices with proration invoice items with proration_behavior=always_invoice because they don’t change the billing amount for the current period.

Manually creating your own prorations

To calculate your own prorations outside of Stripe and add them to the subscription, pass add_invoice_items with a negative unit_amount (equal to the calculated proration amount) to these endpoints:

When prorations are applied

Prorations only apply to charges that occur ahead of the billing period. Usage-based billing isn’t subject to proration.

The prorated amount is calculated as soon as the API updates the subscription. The current billing period’s start and end times are used to calculate the cost of the subscription before and after the change.

Prorations and unpaid invoices

Stripe calculates prorations based on the subscription’s status at the time of an update, assuming that any previous invoices for the subscription will eventually be paid. If a customer changes their subscription while having an unpaid invoice for the current period, they might receive a credit for unused time on the higher-priced plan, even if they haven’t paid for that time yet.

To avoid crediting for unpaid time, you can disable prorations when the subscription’s latest invoice is unpaid. When updating the subscription, set proration_behavior to none. Select one of the following approaches:

To keep the original billing period: Manually create a one-off invoice for any new charges.
To charge immediately for the new plan and reset the billing period: Set billing_cycle_anchor to now. For more details, see Reset the billing period to the current time.

Either of these approaches can lead to double payment if the customer eventually pays the old invoice. To avoid this, void the unpaid invoice.

Taxes and prorations

For information about how taxes work with prorations, see Collect taxes for recurring payments.

Credit prorations

Credit prorations are issued when customers downgrade their subscriptions or cancel subscription items before the end of their billing period. Stripe offers two approaches for calculating credit prorations, depending on whether you set your subscription’s billing_mode to classic or flexible.

Calculation logic with no prorations

In the following scenario, you upgrade a 10 USD monthly subscription to 20 USD with the proration_behavior set to none for 10 days. There’s no previous debit to base it on. Later, you downgrade the subscription to 10 USD per month with the proration_behavior set to always_invoice.

To set up this scenario, first you create a subscription for 10 USD per month on April 1:

The response includes the invoice that’s created for this subscription:

Create subscription response
{
  id: "sub_123",
  latest_invoice: {
    id: "in_123",
    total: 10_00,
    currency: "usd"
    }
}

Then, on April 11, you upgrade the subscription to 20 USD per month without creating prorations:

The latest invoice remains unchanged because proration_behavior is none:

Upgrade subscription response
{
  id: "sub_123",
  latest_invoice: {
    id: "in_123"
  }
}

Finally, on April 21, you downgrade the subscription to 10 USD per month and create prorations:

Classic	Flexible
The `billing_mode=classic` proration calculation logic creates a credit proration based on the current price, even though the customer never paid the 20 USD monthly rate. The latest invoice credits a third of the month for 20 USD (-6.67 USD), even though the customer never paid for the `price_20_monthly` price. It also debits a third of the month for 10 USD (3.33 USD).	The calculation logic enabled with `billing_mode=flexible` creates a credit proration based on the last price billed for the subscription item. In this case, the latest invoice credits a third of a month for the 10 USD monthly price billed on April 1 (3.33 USD) and debits a third of the month for the 10 USD price (3.33 USD). The credit and debit cancel out so the invoice total is 0 USD.
`# billing_mode = classic { id: "sub_123", latest_invoice: { id: "in_456", total: -3_34, currency: "usd" } }`	`# billing_mode = flexible { id: "sub_123", latest_invoice: { id: "in_456", total: 0, currency: "usd" } }`

Calculation logic for coupons applied to multiple subscription items

Stripe weights the amount_off coupon on the credit proration to prevent over-billing.

In the following scenario, a 5 USD coupon is unevenly allocated to a 25 USD monthly subscription for a 10 USD item and 20 USD item.

To set up this scenario, you create a subscription with multiple items and a coupon on February 1:

Which returns this response:

Create subscription with multiple items and a coupon response
{
  id: "sub_123",
  latest_invoice: {
    id: "in_123",
    total: 25_00,
    currency: "usd",
    lines: {
      data: [
      {
        id: "ili_1",
        amount: 10_00,
        price: "price_10_monthly",
        discount_amounts: [{
          discount: "di_a",
          amount: 1_66 }] },
      {
        id: "ili_2",
        amount: 20_00,
        price: "price_20_monthly",
        discount_amounts: [{
          discount: "di_a",
          amount: 3_34
          }]
        },
    ] }
  }
}

To cancel the 10 USD monthly subscription item:

When a subscription item is deleted, the billing_mode associated with that subscription affects how the proration is calculated as follows:

Classic	Flexible
The default behavior distributes a 5 USD coupon to each item (2.5 USD each), canceling the cheaper item (5 USD) and resulting in a refund of 2.5 USD. Stripe calculates the total with the formula `-0.5 x (10 USD price - 5 USD coupon) = -2.50 USD`.	The flexible behavior reflects the proportional discount applied to the canceled item, rather than potentially applying the full discount amount to the proration calculation. Stripe calculates the total using the formula `-0.5 x (10 USD price - 1.66 USD discount amount) = -4.17 USD`.
`# billing_mode = classic { "id": "sub_123", "latest_invoice": { "id": "in_456", "total": -250, "currency": "usd" } }`	`# billing_mode = flexible { "id": "sub_123", "latest_invoice": { "id": "in_789", "total": -417, "currency": "usd" } }`

Preview a proration

You can create a preview invoice to preview changes to a subscription. This API call doesn’t modify the subscription. Instead, it returns the upcoming invoice based only on the parameters that you pass. Changing the price or quantity both result in a proration. This example changes the price and sets a date for the proration.

You can expand the example response below to see:

The credit for unused time at the previous price on lines 36-38.
The cost for time spent at the new price on lines 107-109.
The new subtotal and total for the invoice on lines 276-279.

{
  "id": "upcoming_in_1OujwkClCIKljWvsq5v2ICAN",
  "account_country": "US",
  "account_name": "Test account",
  "amount_due": 3627,
  "amount_paid": 0,
  "amount_remaining": 3627,
  "application_fee_amount": null,
  "attempt_count": 0,
  "attempted": false,

Use this information to confirm the changes with the customer before modifying the subscription. Because Stripe prorates to the second, prorated amounts might change between the time they’re previewed and the time the update is made. To avoid this, pass in a subscription_details.proration_date value when creating a preview. When you update the subscription, pass the same date using the proration_date parameter on a subscription so that the proration is calculated at the same time.

Control proration behavior

Prorating is controlled by the proration_behavior parameter, which has three possible parameter options: create_prorations, always_invoice, and none.

Default behavior

The default parameter for proration_behavior is create_prorations, which creates proration invoice items when applicable. These proration items are only invoiced immediately under certain conditions.

Create immediate prorations

To bill a customer immediately for a change to a subscription on the same billing period, set proration_behavior to always_invoice when you modify the subscription. This calculates the proration, then immediately generates an invoice.

Disable prorations

To disable prorations on a per-request basis, set the proration_behavior parameter to none. No parameter turns off all future prorations for a subscription. To disable prorations indefinitely, set proration_behavior to none for every request that generates prorations:

When prorations are disabled, customers are billed the full amount at the new price when the next invoice is generated.