I'm developing an app, in my app i have three plans,
When a merchant,
1) upgrades their plan by moving from a less expensive charge to a more expensive charge
2) downgrades their plan by moving from a more expensive charge to a less expensive charge
In above situation as a developer which type of actions i have to take,
Solved! Go to the solution
Nick here from Shopify.
This is a really great question. This is something which is out of my scope personally. What I'm going to do is move your post to the Shopify App's board where it will be more likely to get a response and the quality of the answer you need as many other app developers will be checking this board than the Shopify discussion. I hope that's ok.
I also cross-checked your profile and saw you were Shopify Partner and assigned the Partner role to your profile.
All the best, Nick
This is an accepted solution.
As a developer you don't need to do anything extra. When a customer is subscribed to a new plan, Shopify automatically cancels the previous subscription. You just need to subscribe your customer to the new plan as it was the first time.
Here's the documentation for your reference: