> ## Documentation Index
> Fetch the complete documentation index at: https://dev.nickel.com/llms.txt
> Use this file to discover all available pages before exploring further.

# QuickBooks

> How API-created invoices, bills, and payments interact with a connected QuickBooks account

Nickel accounts can connect QuickBooks Online (or QuickBooks Desktop) from the [integrations settings page](https://app.nickel.com/dashboard/settings/integrations). When QuickBooks is connected, Nickel keeps QuickBooks-originated records in sync automatically. This page explains what that means for objects you create through the API — in particular, when Nickel writes to your QuickBooks books and when it doesn't, so you can keep your own bookkeeping without double-recording.

If your account has no QuickBooks connection, none of this applies: nothing you do through the API touches QuickBooks.

<Note>
  In the API, a Nickel invoice is a **payment link** (`POST /paymentLink`). QuickBooks has its own invoice records — this page qualifies which system's invoice it means wherever the two meet.
</Note>

## Receivables: invoices and payments

Whether a payment is recorded in QuickBooks depends on where the underlying invoice came from:

* **Invoices that came from QuickBooks** (imported through the integration, or created in Nickel against a QuickBooks-synced customer with QuickBooks line items) are linked to their QuickBooks counterpart. When such an invoice is paid through Nickel, Nickel records the payment against that invoice in QuickBooks — exactly one payment transaction, deposited to your configured account. Don't also record these manually, or you'll double-count.
* **Invoices created through this API** ([`POST /paymentLink`](/api-reference/payment-link/create-a-new-payment-link)) are Nickel-native and have no QuickBooks counterpart. Payments made on them are **never** recorded in QuickBooks by Nickel. If you keep your books in QuickBooks, record these payments yourself — Nickel won't duplicate them.

Customers created via [`POST /customer`](/api-reference/customer/create-a-customer) exist only in Nickel by default; pass `syncToQbo: true` to also create the customer in QuickBooks Online. This affects only the customer record — it does not cause payments on API-created invoices to sync.

## Payables: vendors, bills, and bill payments

* **Vendors** created via [`POST /vendor`](/api-reference/vendor/create-a-vendor) exist only in Nickel by default. Pass `syncToQbo: true` to also create the vendor in QuickBooks Online at creation time. Vendors that already exist in QuickBooks are imported into Nickel automatically and stay linked.
* **Bills** created via [`POST /bill`](/api-reference/bill/create-a-bill) exist only in Nickel. They are never created in QuickBooks, and their attachments are not uploaded to QuickBooks. (Bills from a connected QuickBooks account are imported into Nickel automatically and appear alongside API-created bills in [`GET /bill`](/api-reference/bill/list-bills).)
* **Bill payments** follow the bill. Paying a bill that was imported from QuickBooks records the bill payment in QuickBooks automatically (QuickBooks Online and Desktop both). Paying an API-created bill records **nothing** in QuickBooks — book the expense yourself.

## Summary

With QuickBooks connected, for objects created purely through this API:

| You do this via the API                            | Nickel writes to QuickBooks            |
| -------------------------------------------------- | -------------------------------------- |
| Create an invoice; a customer pays it              | Nothing                                |
| Mark an invoice paid, refund a payment             | Nothing                                |
| Create a customer or vendor (default)              | Nothing                                |
| Create a customer or vendor with `syncToQbo: true` | The customer / vendor record           |
| Create a bill                                      | Nothing                                |
| Pay an API-created bill                            | Nothing                                |
| Pay a QuickBooks-imported bill                     | The bill payment, applied to that bill |

Nickel never creates standalone deposits, sales receipts, or journal entries for API activity — the rows above are the complete set of QuickBooks writes.