# Overview

In our [Sinch Build Dashboard](https://dashboard.sinch.com/settings/access-keys), you may have noticed that everything you do relating to the Sinch family of APIs is connected to a **project**. In the APIs, this parameter is the `projectId`.

Subprojects are similar to Sinch projects. Like projects, subprojects is a way to group resources together. The main differences to projects are:

- Subprojects exit at the leaf of the account hierarchy and cannot own other (sub)projects.
- Subprojects cannot be directly linked to a billing account. Only a parent project, or `projectId` can link to billing.


Status note:
The subproject API is in closed beta and is available to selected customers only. To discuss access, [contact your account manager](https://dashboard.sinch.com/account/details).

Deprecation:
`v1alpha1` is deprecated in favour of `v1`. New integrations should use `v1`, and existing clients should migrate. The two versions are functionally identical — only the path prefix differs (`/v1alpha1/...` becomes `/v1/...`).

## Use Case

The primary use of subprojects is for scenarios where you act as a reseller for Sinch Products.

You can create a subproject for each one of your customers. If the customer decides to go in another direction, simply remove the subproject.

Usage for each customer is measured separately.

### Example

```mermaid
%%{init: {'theme': 'base', 'themeVariables': { 'primaryColor': '#FFDD99', 'primaryTextColor': '#0A273D', 'secondaryColor': '#FFFFFF', 'secondaryTextColor': 'black', 'fontFamily': 'arial', 'lineColor': '#7F8F99'}}}%%
flowchart TD
    A(Your Corporation) -- owns --- B(Your Sinch Billing Account)
    B --pays for --- C(Direct use project) & D(Resale project)
    D -- Subproject --- E(Customer 1) & F(Customer 2) & G(Customer 3)
```

Getting started with Subprojects API