You can upgrade your Nelio A/B Testing subscription at anytime. Just visit your Account page in Nelio A/B Testing:
There you can click the Upgrade Subscription button that will show you the subscription plans you can select and upgrade to. Once you select the plan you want and confirm, your subscription will be automatically upgraded.
If you need to downgrade your current Nelio A/B Testing subscription plan, please contact us by email at support.testing@neliosoftware.com and we will help you with your demand.