# Blocklists

Use blocklists to prevent fraud and criminal activity.

Blocklists are lists of customer attribute values that are blocked from buying from you.
For example, if a customer attempts to make a purchase from you with a credit card that is in a blocklist, the transaction is blocked and is not processed.

Before a new transaction is processed in Rebilly, blocklists are examined to check for attributes related to the entity.
If a match is detected, the operation is aborted.
A blocklist that expires after a period of time is called a greylist.

## Retrieve blocklists

 - [GET /blocklists](https://www.rebilly.com/docs/dev-docs/api/blocklists/getblocklistcollection.md): Retrieves a list of all blocklists.

## Create a blocklist

 - [POST /blocklists](https://www.rebilly.com/docs/dev-docs/api/blocklists/postblocklist.md): Creates a blocklist.

## Retrieve a blocklist

 - [GET /blocklists/{id}](https://www.rebilly.com/docs/dev-docs/api/blocklists/getblocklist.md): Retrieves a blocklist with a specified ID.

## Create a blocklist with specified ID

 - [PUT /blocklists/{id}](https://www.rebilly.com/docs/dev-docs/api/blocklists/putblocklist.md): Creates a blocklist with a specified ID.

## Delete a blocklist

 - [DELETE /blocklists/{id}](https://www.rebilly.com/docs/dev-docs/api/blocklists/deleteblocklist.md): Deletes a blocklist with a specified ID.