Sinch Voice API: Choosing between v1 and v2
For all new projects, please use Voice API v2. This is especially important for projects involving:

- AI capabilities like Streams and Voice Relay
- Voice campaigns like Batch calling


You should only use the older Voice API v1 if one of the following is a strict requirement:

- The project must be in General Availability (GA).
- The project requires In-App voice or Conferencing (until these features are available in v2).


# Understanding Sinch Accounts and how they affect the Programable Voice

## Account types

### Self created

When a customer creates a new Sinch account via [Sinch Build Dashboard](https://dashboard.sinch.com/signup), they will receive test credits which can be used to make and receive calls. These credits can also be used to test all our voice features (recording, TTS, AMD..) and channels (SIP, Streams, VoiceRelay...).

### Enterprise

For enterprise customers, please contact our sales teams, they can setup a new account for you with special conditions.

Note:
Self created accounts can be converted to enterprise by Sinch, but in many cases, the easier path if you started as self created is just to request a new account from sales. You will be able to set credit limits and eventually special prices.

Additionally Enterprise accounts can be POSTPAID or PREPAID, whereas self created accounts are always PREPAID.

Note:
Our Programmable Voice product does not require provisioning. Once you have your account and have accepted the terms and conditions in the Build dashboard, you can just use it!

## Account status

### Trial vs Upgraded

All self created accounts start as trial, and they are initially limited! Once the account is upgraded by adding a payment method and credits, the account limitations are reduced, which will enable the complete potential of the Programmable Voice product.

#### Trial account limitations:

* Users cannot buy numbers, however, during the first 2 weeks of the trial period, customers will receive a voice enabled test number, which allows the reception of calls (Inbound PHONE calls).
* Users can only DIAL (Outbound PHONE calls) to verified numbers. The phone number used to create the account is automatically verified, but under the Numbers menu, users can add new real numbers they own, and if the verification process is successful each new number will be verified and the account will be allowed to call these numbers.
* Users can only initiate one PHONE call at a time and calls will be limited to a few minutes.
* Once the amount of free credits is consumed, users of self created accounts will need to upgrade or contact the Sinch sales team.


Once the first payment is done, the account becomes an Upgraded account, with little to no limitations. Sinch uses internal mechanisms to evaluate account usage in order to prevent or interrupt fraudulent use cases. As your relationship with Sinch evolves, so do your account's permissions.

Note:
Enterprise accounts can also be created as trial and the same limitations apply, but usually the amount of test credits is larger.

#### Upgraded accounts

* Accounts created by Sinch's sales team are always Enterprise type, and they can be set as PREPAID, POSTPAID, Upgraded or Trial.


## Summary

| Account type | Created by | Account status | Limited | Payment type |
|  --- | --- | --- | --- | --- |
| Self created | Customer | Trial | Yes | PREPAID |
| Self created | Customer | Upgraded | No | PREPAID |
| Enterprise | Sinch | Upgraded | No | POSTPAID |
| Enterprise | Sinch | Upgraded | No | PREPAID |
| Enterprise | Sinch | Trial | Yes | PREPAID |


## Sandbox vs Production

* When we talk about real PSTN (**P**ublic **S**witched **T**elephony **N**etwork) calls, the concept of Sandbox doesn't really apply, as any real PSTN calls must reach the real network, generating real traffic and costs, and we should also consider the regulatory implications of un-registered users making real calls. To solve this issue, we have granted test credits, allowing PSTN calls to registered and verified numbers, and providing a free test number that allows customers to receive PSTN calls to test our phone quality and webhooks behavior.
* Regarding testing, customers can implement SIP or In-app calling, Inbound and Outbound test scenarios, that will enable full webhook and API integration and testing, with minimal costs. Use our test credits for that!
* Regarding CI/CD. Sinch can provide extra test credits to Enterprise customers during the integration and evaluation periods, and after that, CI/CD pipelines that generate real traffic, are considered regular usage of the platform, therefore are treated as production traffic. It is worth reinforcing that Sinch has a pay-as-you-go charging model, which makes the recurrent test process very inexpensive, assuming basic calling functionalities are used, ie: not calling expensive destinations, extremely long calls or stress and load testing, which can become expensive if not managed carefully as it is real traffic.