Trial Shield gives you a disposable, Luhn-valid card number to use when signing up for a free trial, so a trial cannot quietly convert into a paid subscription you never agreed to.
How it works
1. Generate a Trial Shield card from the Trial Shield page.
2. Use it at the merchant's trial signup.
3. The card is single-merchant and capped, so an unexpected conversion charge is declined rather than paid.
4. Flowarden records the trial, its end date, and alerts you before it expires.
Important disclosure
Some merchants place a small authorisation hold to validate the card. That hold is not a charge and drops off automatically, but it does mean a merchant that rejects prepaid-style numbers may refuse the signup. In that case use a real card and rely on renewal alerts and Auto-Pilot instead.
Best practice
- Generate one card per merchant so you always know which service a decline belongs to.
- Note the trial end date; a declined conversion still ends your access, and if you want to keep the service you must add a real payment method.
- Cancel unwanted trials with the merchant as well. A declined charge is protection, not a cancellation.
Limits
Card generation is capped per plan and per period, and caps are enforced server-side. The generation history is shown on the Trial Shield page so you can see what remains in the current period.
When not to use it
Do not use Trial Shield for services you intend to keep, for anything requiring identity-verified payment, or where the merchant's terms prohibit virtual cards.