If you bought a license key for a single year or one domain (eg. to test the plugin) you can still upgrade the license to any higher plan in a few clicks and you will pay only the difference in the price.
To upgrade the license key, please go to following page
Please paste your full license key (you can find it in Permalink Manager settings or in a confirmation email sent shortly after the purchase).
After that, a information page will be displayed where you can find two unique links that would allow you to either prolong or upgrade your license key.
If you decide to upgrade your license key, the initial price will be deducted from the checkout price.
For instance, if you bought a Single domain (one year) license key and paid 40 EUR before, you will get 40 EUR off for a lifetime license key upgrade.