> ## Documentation Index
> Fetch the complete documentation index at: https://billing-help.nace.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Billing app overview

> What the Billing app is and what you use it for

## What is the Billing app?

The **Billing app** is the tool the billing team uses every day to work with NAPA. You use it in your browser—no coding or technical setup required.

## What you can do in the app

* **Upload documents** — Upload contracts, timesheets, and expenses when you’re not using the automatic Barton sync.
* **Trigger and monitor** — Start invoice runs and see the status of jobs (e.g. in progress, waiting for review, completed).
* **Review and approve** — Open invoice drafts, check line items and citations, and approve or reject. You can edit where the process allows.
* **Handle disputes** — Access invoices and supporting documents when a client disputes a charge, so you can review and resolve.

## Who it’s for

The Billing app is for the **billing team**: anyone who needs to create invoices, review and approve them, or resolve disputes. Your manager or IT will give you access and the right link (test, demo, or production). See [Environments](/frontend/environments) for what each link is for.

## Next steps

* **Step-by-step use:** [Using the Billing app](/frontend/using-the-app)
* **Which URL to use:** [Environments](/frontend/environments)