Summary
You can reactivate a subscription by using the Allow Only on Payment Collection option in Subscriptions reactivations settings that restricts the in-term reactivation of canceled subscriptions only upon successful collection of current term charges. 

Go to Configure Chargebee> Billing LogIQ > Subscription reactivation> 'Allow only on Payment collection' 

Solution

When a canceled subscription is attempted to be reactivated, Chargebee has an option to attempt payment collection for the current term charges. 

To reactivate a canceled subscription, follow one of these ways:

• You can click Reactivate Subscription from Chargebee UI.

• Your customers can reactivate the canceled subscription from the Self-Serve Portal (if you have enabled Allow customers to reactivate canceled subscriptions in Portal settings).

• You can also use the Reactivate a subscription  API call to reactivate a subscription via the API

Note: In-term reactivation is currently supported in the In-app Self Serve Portal.

For canceled subscriptions with unpaid invoices, you can choose whether or not you want to allow in-term reactivation before collecting payments for the current term charges. Chargebee gives you the flexibility to manage the in-term reactivation workflow based on your business requirement.

Follow these steps to configure the in-term reactivation workflow in your Chargebee site:

1. Click Settings > Configure Chargebee > Billing LogIQ > Subscription Reactivation. Under the In-term reactivation, you can configure the settings for in-term reactivation of canceled subscriptions.
   

2. The Allow Reactivation option will allow in-term reactivation of canceled subscriptions without making a payment collection of current term charges.

3. The Allow Only on Payment Collection option restricts in-term reactivation of canceled subscriptions only upon successful collection of current term charges. When a canceled subscription is attempted to be reactivated, Chargebee attempts to collect payment for the current term charges once. You can proceed to reactivate the subscription-only when the payment collection goes through successfully.
   
   

4. When you select Allow Only on the Payment Collection option, you can click the more options menu and enable Allow to override via the Chargebee interface. You can even add conditions to this rule by selecting a source and adding the corresponding behaviors.
   
   
   For example, you can allow reactivation only when it is invoked from the Chargebee interface. This way, you can prevent your vast majority of customers from reactivating canceled subscriptions via Portal or API without clearing their current term charges. And yet, when the need comes, you can override via the Chargebee interface to make exceptions for certain customers.

5. Click Apply to save your settings.

When overriding is allowed, you can reactivate the subscription by enabling the Allow reactivation even if payment collection fails the checkbox for the relevant subscription. If payment collection fails, you can still proceed to reactivate the subscription.

Related Documentation

Reactivation - Chargebee Docs

Can I reactivate a canceled subscription? - Chargebee Support

How can I reactivate a subscription using the APIs?