> ## Documentation Index
> Fetch the complete documentation index at: https://docs.traffical.io/llms.txt
> Use this file to discover all available pages before exploring further.
# Usage & billing
> How Traffical counts monthly tracked units (MTU), where to read per-project usage, and how to manage your plan.
The **Billing** page lives in the sidebar's **Organization** section. It shows your plan status, your organization's measured usage, and the controls for upgrading or managing your subscription.
Billing is owner-only: the page requires the `billing:manage` permission, which only the **Owner** role carries — an admin doesn't see it. See [Roles & permissions](/governance/roles-and-permissions).
## How usage is measured
Traffical meters usage in **monthly tracked units (MTU)**: the number of distinct units — users, companies, devices, whatever your project randomizes on — that received **at least one policy assignment** during a calendar month (measured in UTC).
Concretely, a unit is tracked in a given project and month when its unit key appears on at least one [assignment](/concepts/assignments) from a [policy](/concepts/policies) — an experiment, a rollout, or an adaptive policy allocating traffic on a layer. Each unit counts **once per project per month**, no matter how many assignments it receives or how many policies it passes through.
### What doesn't count
* **Serving defaults.** A unit that fetches configuration and only receives parameter defaults — because no policy applies to it — produces no policy assignment and is not tracked.
* **Events alone.** Track events don't count toward MTU. A unit that sends events but receives no policy assignment that month is not tracked. (Event volume is reported separately — see [native project extras](#native-project-extras).)
* **Repeat activity.** The count is distinct units, not assignment volume. A unit assigned a thousand times in a month is one MTU.
### How projects roll up
MTU is counted **per project**, and the organization total is the **sum across projects**. The same user active in two projects counts once in each. Assignments from every [environment](/concepts/projects-and-environments) of a project count, so keep synthetic or load-test traffic out of environments you keep around long-term.
The same counting rule applies whether Traffical stores the project's data or the project runs against [your own warehouse](/concepts/warehouse-native) — in both cases it's distinct units with a policy assignment in the month.
## Reading the usage view
The **Usage** card shows one month at a time. Use the month selector to switch — the current month is selected by default, with up to five prior months available. The headline number is your **organization MTU** for the selected month, with a **Last updated** stamp showing when the numbers were most recently computed; usage refreshes regularly through the month.
A month's numbers are **provisional** while it's in progress and for a few days after it ends — late-arriving data can still land. The card labels the month **month-to-date** with the exact date it finalizes (five days after month end), and **final** once that date passes.
Below the headline, a table breaks the month down per project:
| Column | What it shows |
| ----------- | ----------------------------------------------------------------------------------------------------------------- |
| **Project** | The project key |
| **Engine** | `native` — Traffical stores and processes the project's data; `byo` — the project runs against your own warehouse |
| **MTU** | Distinct tracked units for that project and month |
### Native project extras
For `native` projects, three additional columns report fair-use telemetry:
* **Tracked Events** — total track events received that month.
* **Event Ratio** — tracked events divided by MTU: the average events per tracked unit. Useful for spotting a runaway instrumentation loop before it becomes a conversation.
* **Storage (GB)** — the size of the project's managed event storage. This is a point-in-time snapshot, not a monthly total: the current month shows a live value, and past months keep the last snapshot taken before the month closed.
These columns don't apply to `byo` projects, which store their own data.
## Managing your plan
The status card at the top of the page shows where your organization stands:
* **Trial** — you're in a free trial; the card shows how many days remain and the end date.
* **Active** — your subscription is active.
* **Frozen** — your trial has ended or your subscription has lapsed. Your SDKs keep serving the last published configuration, but configuration changes are paused until you upgrade. Nothing breaks in production; you just can't ship changes.
To upgrade, click **Upgrade Now** — you're taken through a secure checkout and returned to the dashboard with your subscription active.
Once subscribed, **Open Billing Portal** takes you to a self-serve portal where you can update your payment method, view invoices, and cancel your subscription.
This page covers how usage is measured, not what it costs — plan pricing lives on the Traffical website, and your invoices are always available in the billing portal.
## Next steps
What an assignment is and when one is recorded.
Who can see billing, and what each role grants.
How projects and environments are organized.
Common questions, including usage and metering.