Right after the failure
Quick heads-up: your your product payment didn't go through
Hi {{first name}},
We tried to charge your card for your product, but the payment didn't go through. This usually happens when a card expires or the bank flags a charge. Nothing is lost, and your account is still active.
You can update your card in under a minute here: [link to update your card]
If anything looks off, just reply and we'll sort it out.
The your product team