Good afternoon Lucy and welcome to the Events Calendar forum!
Thank you for your interest in our products.
We’ll be glad to answer your questions.
If I want to expand to business within the first year is it possible to pay the difference to expand to the business 3 site version?
Absolutely, there is always an upgrade path available.
You will be able to see this from your License key menu https://theeventscalendar.com/license-keys/
Also is the going to be an annual fee? If I don’t renew it what happens?
Yes. The license is valid for 1 year of updates and premium support forum access.
After that year, your plugin will continue to work.
However, it must be paired with a matching version of our other plugins (released around the same time).
That also holds true of the WordPress version (although, this can last substantially longer).
In other words, if you choose not to renews, you might have to “freeze” your the Events Calendar plugins version (and potentially WordPress as well).
Best regards,
Geoff B.