Billing by batch size
For API flows, billing is based on how many entries are actually included in a mailing batch. The trigger window only decides when a batch is formed. If you do not have enough credit, the batch is not sent; the configuration remains in place and PostPal notifies you. As the payment method, only prepayment and credit are available in a flow - invoice is not possible for API flows.
API flows are billed by the actual batch size. The relevant number is how many entries are really included in a mailing.
The trigger window only controls when PostPal forms a batch. It is not the basis for billing.
If your credit is not sufficient for a batch, it is not sent. The flow remains in place, and open entries can be processed again during a later run.
Payment method in an API flow
Only prepayment and credit are available for API flows. Invoice is not possible - the option is not offered in the flow form and is rejected on save. For regular campaigns and in the account settings, invoice remains usable as before, see Payment method.
The payment method selected in the flow applies to that flow only and does not overwrite your account setting. The invoice address from the flow, in contrast, is additionally stored as the account default.
Frequently asked questions
How is an API flow billed?
It is billed by the actual batch size, meaning the entries that are really included in a mailing.
Is the trigger threshold the billing amount?
No. It only controls when the batch is formed.
What happens if there is not enough credit?
PostPal does not send the batch, keeps the flow configured and notifies you about the missing credit.
Which payment methods can I choose for an API flow?
Only prepayment or credit. Invoice is not available for API flow batches, but remains selectable for regular campaigns - see Payment method.
Does the payment method in the flow change my account setting?
No. The payment method applies to that API flow only. The invoice address from the flow is saved as the account default though.