How can I upgrade to the higher tier subscription and how much will it cost?

If you currently have a free registration or basic paid subscription you can upgrade to the higher tier subscription at anytime from your Account Settings page. 

• Sign in to your account.
• Click the avatar or account link in the top right of the signed in page.
• Choose Account Settings from the dropdown.
• Choose "Manage subscription" from the settings page.
• Choose the higher subscription tier from the “Available plans” on the page.
• Review and agree to the subscription plan details and click confirm

Note: If you purchased your subscription from an app platform, you are not able to upgrade to the higher tier subscription. You will need to cancel your app subscription, and wait until your access expires before you can purchase a higher tier subscription via the website checkout.  

The price you will be charged to upgrade is determined by the amount you paid in your previous charge and the number of days remaining until your next charge. The pro-rated price is calculated by taking the amount you paid for the subscription divided by the days in the billing cycle, multiplied by the number of days until the next billing cycle. This price is then subtracted from the price of the higher-tier subscription. After your first prorated subscription charge, subsequent charges will be at the full list price. 

Similarly, if you were gifted a subscription and want to upgrade, your price will be calculated by taking the initial cost of the gift and the number of days remaining however instead of discounting the price, your subscription will be extended by a number of days equivalent to the remaining value of your gift.