UPDATE 15/09/2012WhatsApp version 2.8.4 was just released. It now supports 30 people per group chat.
WhatsApp has just silently increased the maximum number of people in a group to yourself plus fifteen others. In fact, I didn’t know about it until a friend told me, and I was in disbelief as my iPhone showed I was already at the maximum with 10 other people in the group.
Here’s how you can increase your group size.
1. Upgrade WhatsApp to the most current version via the App Store.
2. Open up your group chat and click on the Info button at the top-right corner. You’ll probably see that you have 10 of 10 participants. Ignore what it says, scroll to the bottom and click “Add Participant” anyway.
3. After you select someone and add him/her in, you will automatically be bumped up to 15 other participants in the group!