# Introduction to User Acquisition billing

> Review how campaign billing work with Unity User Acquisition.

User Acquisition billing is how your Unity Organization is charged for your User Acquisition campaigns. Your campaign goal determines your billing type. Refer to the following table for each campaign goal and its associated billing type:

| Campaign Goal                                                                                                                                                                                                                                                     | Billing type           | Billing type description                                                                                                                               |
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------ |
| [Creative Testing](/user-acquisition/campaigns/creative-testing/creative-testing-campaigns.md)                                                                                                                                                                    | Cost per mille (CPM)   | Charged for every 1000 impressions (also known as [Starts](/user-acquisition/data-sharing/ad-metrics-data-sharing.md#starts)).                         |
| * [Install](/user-acquisition/campaigns/install/cost-per-install-campaigns.md)
* [Return on Ad Spend](/user-acquisition/campaigns/roas/return-on-ad-spend-campaigns.md)
* [Event Optimization](/user-acquisition/campaigns/event/event-optimization-campaigns.md) | Cost per install (CPI) | Charged for installs [attributed](/user-acquisition/data-sharing/attribution/campaign-attribution-fundamentals.md#attribution-links) to your campaign. |

Creative Testing campaigns use CPM billing because they're designed to test creative performance rather than optimize for installs. These campaigns distribute impressions equally across your creatives to ensure fair testing, so billing is based on impressions (CPM) rather than installs (CPI).

All other Unity User Acquisition campaigns use CPI billing, and you only pay for converted installs. If your campaign accrues more than 10k impressions (starts) without any installs in the last 24 hours, Unity converts your campaign to CPM billing.

## Prepayments

With User Acquisition, you prepay your campaigns by adding funds to your [Organization budget](/user-acquisition/billing/add-funds.md). Access the organization budget from the **Billing** page of the dashboard.

You can add funds using a credit card or Alipay. The minimum deposit amount for credit cards and third-party payment platforms is $1,000 USD. If you want to deposit more than $10,000 USD, contact your account manager.

If you also monetize your app with Unity, you can transfer ad revenue funds from your monetization account. [Refer to the User Acquisiton Transfer](/monetization/payments/transfers/user-acquisition-transfers.md) documentation for more information.

## Post payments

Advertisers with managed accounts can work with a client partner to set up post payments. These accounts use a credit line to fund the Organization budget, and advertisers make payments on a monthly basis. Access to post-payments is available based on advertisers' payment history.

If you don't have a Unity account manager and need help with credit lines, use the Unity Ads Support [contact form](https://support-ads.unity.com/s/ContactUs) to request help.

When you set up post payments, the **Total budget available** card on the **Billing** page shows **Credit limit** instead of a balance amount. If an account exceeds its credit limit, the dashboard will display **Out of credit** instead.

> **Note:**
>
> When a managed account is close to its credit limit, your client partners contact the advertiser. For additional information about post payments and credit limits, contact your client partner.

## Budgets

[Campaign budgets](/user-acquisition/budgets/intro-to-budgets.md#campaign-budget) control how much of your Organization budget each campaign can use. To control how much your campaign can spend each day, you can also set [Daily budgets](/user-acquisition/budgets/intro-to-budgets.md#daily-budget) for your campaigns. When your campaign reaches its daily or total campaign budget, Unity pauses ad delivery. Refer to the [Introduction to User Acquisition budgets](/user-acquisition/budgets/intro-to-budgets.md) for more information.