# Purchasing Lookups

A lookup balance is our form of credit which permits one valid address search.

Each account can produce one or more API Keys. Our [lookup guide](https://addresszen.com/guides/what-is-a-lookup) explains what kind of search affects your lookup balance.

We recommend automating your balance procurement through one of our Automated Top-Up plans. However, you can also choose to manually purchase lookups at any time.

When a new batch of lookups is procured, it will expire 12 months from the date of **first use** - i.e. not the purchase date.

Batches will be drawn down in the order they are purchased - i.e. oldest batches are consumed first and newest batches are saved until last.

## How to Purchase Credits[​](#how-to-purchase-credits "Direct link to How to Purchase Credits")

For a one time purchase, follow the steps below:

1. On the left hand side of the dashboard, click on the `Keys` tab.

2. Click on the blue `Manage` button on your API Key.

3. On the right hand side of the dashboard, you will see your current balance in a bright green box. Click on the blue `One Time Top Up` button

4. Enter the credit block you would like to procure. A block corresponds to 100 credits/verified addresses. Each purchased batch of credits will expire a year after initial use.

5. Enter your payment details and click `Make Payment`.

## Automated Top-Ups[​](#automated-top-ups "Direct link to Automated Top-Ups")

You can also set up Automated Top-Ups, whereby your API Key will be topped up when your balance runs low, keeping you notified.

Follow the [Automated Top-Ups guide](/docs/guides/automated-topups.md) to find out how to enable this.