> ## Documentation Index
> Fetch the complete documentation index at: https://docs.tracklysms.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Platform Limits

> Reference for all rate limits, payload sizes, and resource limits across the Trackly SMS platform

You can send high volumes through the Trackly SMS API, but certain limits apply to protect platform stability and ensure fair usage.

## API Limits

| Limit                              | Value       | Notes                                         |
| ---------------------------------- | ----------- | --------------------------------------------- |
| Messages per bulk request          | 1,000       | Use `POST /v2/send/bulk`                      |
| Contacts per bulk request          | 1,000       | Use `POST /v2/contacts/bulk`                  |
| Revenue records per bulk request   | 1,000       | Use `POST /v2/revenue/bulk`                   |
| History records per import request | 1,000       | Applies to sends, clicks, and revenue imports |
| API payload max size               | 5 MB        | Per request                                   |
| Contact payload max size           | 4,000 bytes | Per individual contact object                 |
| OTP metadata max size              | 1,024 bytes | Per OTP verification request                  |

## Messaging Limits

| Limit                       | Value               | Notes                                        |
| --------------------------- | ------------------- | -------------------------------------------- |
| Default send rate           | 17,000 messages/min | Per sending list, configurable by support    |
| Message template max length | 1,600 characters    | Across all segment types                     |
| Stale message threshold     | 30 minutes          | Messages queued longer than this are dropped |
| Free tier monthly limit     | 500 messages        | Per account, resets monthly                  |

## Contact & Import Limits

| Limit                         | Value | Notes                        |
| ----------------------------- | ----- | ---------------------------- |
| Contacts per CSV import       | 5,000 | Via dashboard upload         |
| Contacts per API bulk request | 1,000 | Via `POST /v2/contacts/bulk` |

## Journey Limits

| Limit                  | Value   | Notes                                             |
| ---------------------- | ------- | ------------------------------------------------- |
| Max journey executions | 1,000   | Per journey enrollment batch                      |
| Max journey duration   | 30 days | Journeys automatically complete after this period |

## Billing Limits

| Limit             | Value      | Notes                                                                          |
| ----------------- | ---------- | ------------------------------------------------------------------------------ |
| Billing block TTL | 60 minutes | Accounts with expired billing are blocked for up to 60 minutes before re-check |

## Requesting Increases

If you need higher limits for any of the above, contact support at [support@tracklysms.com](mailto:support@tracklysms.com). Include your account ID and the specific limit you need adjusted.

Send rate increases require a review of your sending patterns and compliance history.

## Next Steps

<CardGroup cols={2}>
  <Card title="API Limits & Best Practices" icon="gauge" href="/api-reference/v2/rate-limiting">
    Payload limits, batch sizes, and retry strategies
  </Card>

  <Card title="Send First SMS" icon="paper-plane" href="/quickstarts/send-first-sms">
    Get started sending messages
  </Card>
</CardGroup>