If you can't upgrade your HQ, you either lack in level or in resources.
- If you have all your storages full to the brink, and they are upgraded to the maximum levels available, but you still don't have enough resources to upgrade your HQ, try upgrading your Bunker, because it slightly increases the storing capacity for all resources.
- In addition to resources, each HQ upgrade also requires you to have reached a certain level. Your level is displayed in the upper left corner of the screen next to your avatar. To level up, earn experience points by upgrading other structures, or units and abilities in the Arsenal.