Expired card email
Ask for a card update without implying churn.
Why this works
Expired cards usually need customer action, so the update link should be the main call to action.
Subject
Can you update your card for {{product_name}}?
Email body
Hi {{first_name}},
We tried to renew {{product_name}}, but Stripe says the card on file has expired.
You can update the card here: {{stripe_update_link}}
Once that is done, we will retry the payment automatically. Nothing else is needed from you.
Thanks,
{{sender_name}}