How do I add custom notes to an individual subscription?

You can add custom notes to an individual subscription, that will be visible on invoices generated for that subscription going forward by completing the following steps:

1.) Go to the Subscription you'd like to edit on the customer's account details page and click Options->Edit Subscription
2.) On the Subscription Edit Page scroll down to the "Note To Customer" box, under Invoicing and add your notes to the text box.
3.) Keep the radial button for Apply Changes Immediately selected
4.)Save Changes.

If the only edit you are making to the subscription is to add the customer note, no invoice will be generated at the time of the change, and you will just see the note included on invoices generated for that subscription going forward.

Please feel free to reach out should you have additional questions or concerns.