These are some things to keep in mind if you change your Arduino Cloud plan from a paid plan to a free or cheaper plan.
Your plan is valid until the end of the billing cycle
When requesting a downgrade, your current plan will be active until the end of the billing cycle. You will retain access to all plan features until then. In the meantime, the plan change will appear as queued in your account, where it can be canceled if you change your mind.
Feature limits may be exceeded
When the plan change goes into effect, new feature limits will apply to your account. If these limits are exceeded, certain features may be disabled.
If you have exceeded the limit on the maximum number of sketches allowed in your sketchbook, you can still view all of your sketches. However, you cannot edit them. To enable editing, delete sketches until you're within your plan limit.
Things and variables
If you have exceeded the limits on Things or variables, you cannot see Things dashboard data or connect your devices to the cloud. To enable Cloud features you have to delete Things and variables exceeding your plan limits.
Cloud-enabled Linux devices
If you have exceeded the limit on Cloud-enabled Linux devices, you will be unable to see device details, control them or connect them to the cloud. To enable these features you have to delete devices exceeding the limits of your plan.