# About Messaging Limits

Understanding messaging limits is crucial for effectively engaging with your customers through the WhatsApp Business API. The messaging limit refers to the maximum number of business-initiated conversations you can start in a rolling 24-hour period. A business-initiated conversation begins when the first message is delivered to a customer and concludes 24 hours later.

If you reach your messaging limit, you can initiate more conversations as soon as one or more active conversations end.

### **Messaging Limits Based on Verification Status:**

* **Unverified Business**:\
  You can initiate conversations with **250 unique customers** in a rolling 24-hour period.
* **Verified Business**:\
  The limits vary based on your tier:
  * **Tier 0**: 250 business-initiated conversations
  * **Tier 1**: 1,000 business-initiated conversations
  * **Tier 2**: 10,000 business-initiated conversations
  * **Tier 3**: 100,000 business-initiated conversations
  * **Tier 4**: Unlimited business-initiated conversations

### **Upgrading Tiers:**

To upgrade between tiers, you must also maintain a quality rating of High or Medium. Here’s how the upgrades work:

* **Tier 0 to Tier 1:**\
  Start a single business-initiated or reply to a user-initiated conversation.
* **Tier 1 to Tier 2:**\
  Engage with 500 unique customers in a 7-day rolling period.
* **Tier 2 to Tier 3:**\
  Engage with 5,000 unique customers in a 7-day rolling period.
* **Tier 3 to Tier 4:**\
  Engage with 50,000 unique customers in a 7-day rolling period.

Maintaining a high quality rating is crucial for sustaining your tier level and enhancing your messaging capabilities.

### **What is a Rolling Period?**

The rolling period is calculated based on the current date. For instance, if you initiated conversations with **499 unique customers** 7 days ago and do not engage any additional customers, those **499 customer conversations** will no longer count towards your limit as the period rolls forward. It's essential to keep this in mind to maintain your messaging capabilities effectively.