---
title: "Billing Period Calculations"
source_url: https://docs.rapyd.net/en/billing-period-calculations.html
lang: en
---

# Billing Period Calculations

The following information explains how the billing period is determined.

**Billing Period Start**

The start of the billing period is affected by the setting of the `trial_end` field. Trial periods are defined in the 'subscription' object.

**No Trial Period**

If there is no trial period at all, `trial_end` is null, and the current billing period starts at the date indicated in `current_period_start`.

**Trial Period Expires Before Current Billing Period**

If the trial period ended before the start of the current billing period, the date in `trial_end` is before the date in `current_period_start`, and the current billing period starts at the date indicated in `current_period_start`.

**Trial Period Expires During Current Billing Period**

If the date in `trial_end` falls in the current billing period, the charge is prorated, starting at the date indicated in `trial_end`.

**Billing Period End**

The end of the billing period is affected by the settings of the `prorate` and `proration_date` fields. Proration dates can be determined in either the Subscription object or individual Subscription Item objects. Proration settings in the Subscription Item take precedence over the Subscription object.

**Charges Are Not Prorated**

If `prorate` is **false** or null, the current billing period ends at the date indicated in `current_period_end`.

**Charges Are Prorated**

If `prorate` is **true**, the current billing period ends at the date indicated in `proration_date`.