When the subscription has been created it uses the product plan as a reference, and reference each of the product plan charges. This reference is an object called subscription charge.
The Subscription Charges will automatically receive the default quantities and settings from the Product Plan, and depending on your Upodi setup this will often require that you set the appropriate quantities.
**Billing cycle** As each billing cycle is run, a new set of subscription charges are created and the former set will be marked as processed. This keeps a reference over time to allow tracking of the subscription lifecycle. When a subscription charge is due, the billing cycle will mark the subscription charge as processed, by setting the field [_previous charge date_](🔗), to the time of the billing process, and creates a new version of the subscription charge for future billing by setting the [_next charge date_](🔗) field; unless the subscription is ended.
The output of a subscription charge is an invoice line. Should a given billing cycle return multiple subscription charges, the generated invoice will include more lines.
## What's Next
Please visit [the conceptual](🔗) model for relationships.
If you are a developer you probably want to review the [endpoints for subscription](🔗) and the [subscription object](🔗).
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