You may add additional Matters to your current subscription in AppColl using the following steps: 

1. Hover over the Settings gear icon and select Manage Account.
2. Click the Logins / Matters tab.
3. In the Matters row, select an option from the Additions as needed. If you have maxed out your matters, increase the number of Users in the above column. (See Add Logins to Your Account).

4. Review the next payment date and any prorated cost amount as needed. Click the Save Changes button. 

5. Log out and then log back in to put the changes into effect.