# Implementation use cases

This section contains use cases and scenarios to help you implement the Policies API.

## Assigning a cancellation policy to a roomrate

The diagram below shows how a property with the following resources can create 3 or more roomrates:

- 2 room types
- 2 rate plans, and
- 2 policies


Note that the property has created 3 roomrates each with a combination of room type, rate plan and a cancellation policy. You can specify any combination of existing room types, rate plans and cancellation policies to create more than one roomrate.

- To create a room type, use the [OTA_HotelInvNotif](/connectivity/docs/room-type-and-rate-plan-management/managing-room-types#creating-a-room-type) endpoint
- To create a rate plan, use the [OTA_HotelRatePlanNotif](/connectivity/docs/room-type-and-rate-plan-management/managing-rate-plans#creating-a-rate-plan) endpoint
- To create a roomrate and assign a policy to it, use the [OTA_HotelProductNotif](/connectivity/docs/room-type-and-rate-plan-management/managing-roomrates#creating-a-roomrate) endpoint


![Understand Policy API](/assets/understanding-policies.7573c3507a696add80736ec4d995b9d4694d0c15f9d491d0460a43f2cb877b26.fadde85f.png)

**Figure 1.** A simplified view of how room type, rate plan and policy interact to create a roomrate.

Cancellation policies are assigned at the roomrate level
Policies are assigned on the roomrate level using a policy ID. When creating a roomrate, you must select an existing room type, rate plan and a policy (if you do not want the API to assign the default policy).

## Policy change impacts roomrates

The Policies API enables you to change the details of a policy even when it is assigned to a roomrate. After the change, the roomrate uses the updated policy rules.  The following figure shows how changing a policy impacts the existing roomrates with the policy assigned to them.

![Actions on policies](/assets/actions-on-policy.7ed7834048d933c945626eceebc994ec63d1d5a4b2133dafd0fc80f8ed071c41.fadde85f.png)

**Figure 2.** Actions on a policy.

## Support and feedback

If you have questions or suggestions for improvement, please feel free to [contact us](https://connectivity.booking.com/s/article/Contact-Us?language=en_US).

### What's Next?

→ To create a policy, see [Creating a policy](/connectivity/docs/policies-api/managing-policies#creating-a-cancellation-policy).

→ To modify policy details, see [Changing policy details](/connectivity/docs/policies-api/managing-policies#changing-policy-details).