Skip to main content

​
Overview

To protect platform stability and carrier relationships, Telnyx enforces a dials per second (DPS) limit on outbound dial attempts. This limit caps how many new outbound call legs your account can start per second. The DPS limit applies to dial attempts made through:
The DPS limit governs the rate at which new outbound legs are started. It is independent of concurrent call limits, which cap how many calls can be active at the same time. You can be well under your concurrent call limit and still hit the DPS limit if you start too many calls too quickly.

​
Default limit

By default, every account is limited to 30 dials per second.

​
How it’s calculated

The limit is not a strict per-second token bucket — it is calculated as a 5-second rolling aggregation. Telnyx sums the number of dial attempts made in the trailing 5-second window and compares that total against 30 × 5 = 150. If a new dial attempt would push the 5-second total over that threshold, the request is rejected. This means brief bursts above 30/sec are tolerated as long as the 5-second average stays at or below the limit — but sustained dialing above 30/sec will trigger the limit once the rolling window fills up.

​
Error response

When the DPS limit is reached, the dial attempt is rejected with an HTTP 429 response:
Example as seen from an SDK call:
This applies uniformly regardless of which interface originated the dial attempt — Voice API Dial, TeXML <Dial>, or the TeXML REST API.

​
Handling the limit

​
Client-side pacing

The most reliable way to avoid 90103 errors is to pace outbound dial attempts on your side so you never submit more than 30 requests per second (averaged over any 5-second window).

​
Retry with backoff

If you receive a 429 with error code 90103, treat it like any other rate-limit response:
  1. Do not retry immediately — wait at least 1 second before the next attempt.
  2. Use exponential backoff if the error recurs.
  3. Queue and smooth out bursts of outbound calls (e.g. campaign dialers, click-to-call bulk actions) rather than firing them all at once.

​
Requesting a higher limit

If your use case requires dialing faster than 30 dials per second — for example, outbound dialing campaigns, contact center bulk dialers, or call tracking systems — contact Telnyx support to request a limit increase.
Increasing your DPS limit does not change your concurrent call limit. If your campaign also needs more simultaneous active calls, request both increases together.