Downgrading your QuickBooks Online plan won't lose your data, Geetika.
When you downgrade your QuickBooks Online plan, your data is generally not lost. However, some features and associated data will be affected. For example, QuickBooks Advanced offers the ability to manage up to 25 users, so you'll need to remove any users that exceed the 5-user limit of the Plus plan.
Other features you'll no longer have access to include customized roles, some report customizations, and the built-in backup and restore tool. You can also check out this article about user limits for each plan.
Regarding billing, you will not receive a prorated refund for the remainder of your current billing cycle. Instead, the downgrade will take effect at the beginning of your next billing period because it is considered a new subscription, which means a new payment will be required. You can continue to use all the features of your Advanced plan until that time.
To ensure a smooth transition, we highly recommend exporting important reports and creating a backup of your data before you downgrade. This will guarantee that you have a copy of everything you need, just in case.
For more information about the features available on each plan and the data you'll need to turn off, remove, and deactivate for an easy subscription downgrade, check this article: Upgrade or downgrade your QuickBooks Online subscription.
Feel free to go back to this thread if you have more questions.
