Invoice & Billing Integrations

This guide covers the lifecycle of invoices, how to handle corrections, and the details of invoice line items.

1. Invoice Lifecycle and Availability

Invoice Generation Timeline

Understand when invoices are generated and become available via the API.

1. Generation: Invoices are generated on the 4th of the month.
2. Internal Approval: Invoices are reviewed and approved by internal teams shortly after generation.
3. API Availability: An invoice is made available via the API as soon as it is approved.
4. Email Distribution: Emailed invoices begin sending to partners on the 5th of the month.

• Potential Delays: If errors are detected before an invoice is approved, Pax8 may regenerate the invoice. This will delay the approval and, consequently, its availability via the API. You can subscribe to our "invoice ready" webhook event to be notified when invoices are ready.

Invoice Immutability and Corrections

Once an invoice is approved, its contents are final and cannot be changed.

• Pre-Approval: As of November 2025, invoices that are not yet approved may be voided and regenerated internally. These voided invoices will not appear in the API's invoice list.
• Post-Approval: An approved invoice cannot be edited or voided for any reason.

Handling Corrections to Approved Invoices:
If an approved invoice contains significant errors and must be regenerated, the following process is used:

1. The incorrect, approved invoice is "Credited" in full.
2. This "Credited" invoice will still be visible in your invoice list and accessible via the API.
3. A ledger credit for the full invoice amount is generated, which will be included on the next credit memo.
4. A new, corrected invoice is generated with a new invoice number.

Key Takeaway: You will not see an approved invoice change. Instead, you will see the original invoice marked as "Credited" and a new invoice issued with the corrected details.

Understanding Key Invoice Fields

The following fields are present on the invoice object:

• total: The total of all charges and applicable sales tax for the previous billing period.
• carriedBalance: The unpaid balance from the previous invoice that is carried forward to the current invoice. (Note: This information will soon be moved to the Account Statement and removed from the invoice itself).
• balance: The total account balance due to Pax8.
• currencyCode: The ISO currency code for the partner's default currency. Every invoice is in this currency.

2. Line Item Details

Service Charges

We use different types of service charges. Here is what to expect from those line items:

• Types: Charges can be "general" or "product related."
• Product-Related Fields: These charges provide the option to select a vendor, subscription, product, and customer.
• Required Fields: All service charges will have a transaction date, billing start period, and billing end period.
• Optional Fields: quantity is not a required field but is typically included in the description when applicable. Sales tax may be included or excluded depending on the situation.

Important Change to Reconciliation:
Previously, missed subscriptions were sometimes added using a service charge. This practice has been discontinued.

When we detect subscriptions that were missed in a billing cycle, we now upload them upstream from invoice generation. They will appear on your invoice as normal charge line items, not as service charges.

Subscription ID (subscriptionId)

The subscriptionId is a UUID used to link an invoice line item back to a specific subscription.

• Key Behavior: This subscriptionId increments (i.e., a new UUID is generated) every time there is a modification to the subscription, such as a quantity or price change. In the online Pax8 portal, you can see these different incrementing subscriptionIds.
• For purposes of our public APIs, the subscriptionId will always return the original subscriptionId. You can still use our subscription history endpoint to see the changes in subscription history and ids.
• Each invoice line item includes the "subscriptionId" related to that line item charge, that you can use to cross reference the respective subscription.