Yes, you can upgrade your VPS after signing up and pretty effortlessly too. You have to login to your account and visit the billing page. Click on products and services and click on the details tab provided next to the
VPS plan you want to upgrade. An upgrade/downgrade package option will appear. Choose the appropriate package you want to upgrade to and pay the relevant stated on the page. After your payment is approved, your VPS account will be upgraded. For your upgraded account resources to be activated, you will have to reboot the
server. Operating System does not require any reloading.