The VIP Vault is a reward cache that opens up every month. The base vault rewards scale with your current VIP rank and you can add more rewards by completing VIP XP Milestones. You can check the progress towards your next VIP XP Milestone and the current rewards in your VIP Vault on your VIP Profile page.

If you reach max VIP rank, you can still unlock milestone rewards to contribute to your Vault by continuing to earn VIP XP.