- Account-level quotas
- Dynamic rate limits
- Phone number pools
Account-Level Quotas
Enterprise Plans
For larger organizations with higher messaging volume, our Enterprise plans provide flexible quotas that scale with your business. Enterprise access is granted on an application basis to maintain platform integrity and combat spam. Each enterprise account starts with a quota based on your approved use case (usually defined as a monthly message limit). If you’re nearing your quota, you can request an increase.- Requests for quota increases are typically fulfilled within 2 weeks per 1M additional monthly messages.
- Example: A request to add 2M messages/month is guaranteed within 4 weeks, though we often fulfill much faster.
Rate Limits
Arnio enforces rate limits at both the contact level and the conversation level to ensure reliable delivery and compliance with Apple’s policies.| Limit Type | Description | Rate limit* |
|---|---|---|
| New contact outreach | Maximum number of unique contacts you can initiate per phone line, per day. | 50 new contacts/day per line |
| Per-conversation limits | Once a conversation exists, you can continue messaging that contact, but each conversation is subject to pacing. | 20 messages/minute 600 messages/hours 2,400 messages/day |
| Message pacing per line | Each phone line can send at a rate of ~1 message per second. Scaling requires number pooling. | 1 message/second/line |
Key Notes
- If you have 10 phone lines, you can start up to 500 new conversations/day across your account.
- Ongoing conversations are not capped by Arnio in total, but each conversation must respect the pacing limits above.
- Arnio reserves the right to throttle or block accounts that exceed limits in ways that risk spam classification or service stability.
Number Pooling
To reach more contacts or increase throughput beyond what a single phone line can handle, Arnio supports number pooling. By assigning multiple phone lines to your account, you can scale outbound messaging rates proportionally.- Example: If you need to send ~100 messages per second, you would need 100 phone lines in your pool.
- Even though Arnio may deliver from any number in your pool, each recipient always sees a consistent number. If a customer first hears from you via +1 999 888 7777, all future conversations with that customer will stay on that number, ensuring continuity and trust.
Message Queueing
Arnio automatically queues outbound messages as they reach our API.- If you submit 10 requests simultaneously, they will be paced out at one message per second per line.
- Each account has a queue window of up to 1,500 pending messages. Beyond this, Arnio will return a 429 - Too Many Requests response.
- Using number pooling allows you to expand throughput and reduce queue delays.
Messaging Limits
Messaging limits are based on how phone lines are attached to your account.- If you exceed your plan’s monthly allowance, Arnio will not hard-stop your messages.
- Additional usage will be billed at $0.015 per message
- For rapidly growing accounts, we strongly recommend upgrading your plan early to secure the lowest possible cost per message.