Does not allow to increase the plan

There was an error processing your request.

Hi Alex, 

Welcome to Box Community and glad to help! 

If you're having trouble upgrading your Box account yourself. You may contact our Sales team for assistance,

Here's how: 

1. You can give them a call directly at 1.877.729.4269 ext. 1
2. Submit a contact form at this page: https://www.box.com/quote/
3. View package options and live chat sales (available during US business hours) at this page: https://www.box.com/pricing/

Hope it helps!