Card declined or payment failed at Whizi checkout

The short answer

If your card was genuinely declined, the refusal came from your bank through Stripe, not from Whizi, so the fix is a different card or a call to your bank. Whizi does not have a card declined message anywhere in it. Card details are entered on Stripe's hosted checkout page, which sits outside Whizi's codebase, and Whizi's Stripe webhook handler has no declined payment message to show you.

So if you saw an error with Whizi wording on it, it was not a decline. It was one of the strings below, and each one has a different cause and a different fix.

The three that are easiest to mistake for a decline:

What you saw	What it means	What to do
A $0.99 intro trial has already been used with this payment method.	That card has already claimed the intro trial	Subscribe at the normal rate, or use a card that has not claimed it. Retrying will not work
Pricing is temporarily unavailable.	Whizi could not read the price table from Stripe	Wait and try again later. Nothing on your side fixes this
Failed to create Stripe checkout session.	The checkout call failed and the backend supplied no message	Retry once. If it repeats, contact support

Every error the Whizi backend returns at checkout

These come from the server, so they arrive with an HTTP status and an error code that support can match in a network trace. Every backend error body is JSON in the shape {"error": {"code": "...", "message": "..."}}, so the code sits next to the message. The rows below are ordered by HTTP status.

Message	HTTP	Code	Triggered when
A plan and billing cycle are required.	400	invalid_checkout_request	The checkout body could not be parsed
Invalid plan or billing cycle.	400	invalid_plan_or_cycle	The plan or cycle does not map to a known Stripe price
No subscription item found for the active subscription.	400	subscription_item_missing	An in place plan change ran against a subscription with no item on it
The supplied discount must be an active 100% promotion code or coupon ID.	400	invalid_discount	The code supplied is not an active 100 percent promotion code or coupon ID
Temporary email addresses are not allowed. Please use a permanent email address.	400	disposable_email_blocked	The signed in account's email is on the disposable domain list
A $0.99 intro trial has already been used with this payment method.	403	duplicate_trial_payment_method	The card fingerprint has already claimed the intro trial
User not found.	404	not_found	The checkout route could not read your user row
Pricing is temporarily unavailable.	503	pricing_unavailable	The localized price table could not be read from Stripe

What to do with each. The intro trial refusal has its own section below. Pricing is temporarily unavailable. is server side: HTTP 503, returned when the localized price table cannot be read from Stripe, and there is no setting on your account that changes it. Failed to create Stripe checkout session. is not a server message at all, which is why it names no reason: it is the website's own fallback text, shown when the checkout call fails and the backend supplied no message. Both are wait and retry.

A plan and billing cycle are required. and Invalid plan or billing cycle. both mean the request did not carry a plan the server recognises, so start again from the pricing page and pick the plan and the monthly or annual toggle there rather than reusing an old or edited checkout link.

User not found. means your session points at a user row the server cannot read. Sign out, sign back in, then start checkout again.

No subscription item found for the active subscription. fires during a plan change rather than a first purchase, and it is not fixable from the interface. Contact support.

Errors the website shows before checkout even opens

These come from the browser, not the server, so they have no HTTP code. They all mean the same broad thing: something failed while Whizi was preparing your account for the handoff to Stripe, so no charge was ever attempted.

Message	Triggered when
Failed to create Stripe checkout session.	The checkout call failed and the backend supplied no message
Could not open checkout. Please try again.	The upgrade modal's checkout call threw with no message
Authentication failed. Please sign in again.	The token fetch returned nothing before checkout
Failed to save user before checkout.	The pre checkout user save call was not OK
Could not prepare your account for checkout.	The pricing page could not save the user before checkout
Missing user or Stripe customer details.	The user id was absent at checkout time
Checkout response did not include a Stripe URL.	Checkout succeeded but returned neither a URL nor a subscription id
Something went wrong while starting your trial. Please try again.	The pricing page's generic trial start failure

For anything on this list, sign out, sign back in, and start checkout again from the pricing page. That clears the cases where the token fetch returned nothing before checkout, which is what Authentication failed. Please sign in again. reports.

Checkout response did not include a Stripe URL. is the one worth pausing on. It means the call succeeded, so before you try to pay again, open your account settings and check whether a subscription is already there.

Two more appear on the sign in and sign up pages when you pick a plan first and authenticate second: Signed in, but checkout could not start. Please choose your plan again. and Your account was created, but checkout could not start. Please sign in and choose your plan again. Both mean the account part worked and only the handoff failed. Your account exists. Go to pricing and pick the plan again.

One last cause of a mysterious failure: retrying checkout many times in a row can trip the rate limiter, which returns HTTP 429 and Too many requests. Please wait and try again. Every request on the account, whatever the route, counts against a ceiling of 30 per minute. Wait a minute rather than clicking again.

The intro trial refusal, which no retry will clear

A $0.99 intro trial has already been used with this payment method. is HTTP 403 with the code duplicate_trial_payment_method. It is the one checkout error on this page that a retry will never clear.

The check is keyed to the card rather than to the account: the refusal is returned when the card fingerprint has already claimed the intro trial.

Your two options: subscribe at the standard rate for the plan you want, or pay with a payment method that has not claimed the trial before.

Plan prices, the trial terms and what happens at conversion are all in billing, trials and how to cancel.

Payment went through but the account is still on the free plan

A charged card plus an account that still behaves as free is a different symptom from checkout failing, and it has its own page.

Read you paid but the plan features are still locked for the strings that appear in that state, the check that tells you which account holds the subscription, and what to send support.

What Whizi cannot tell you

Three gaps, so you do not spend time hunting for answers that are not there.

Whizi never sees why your bank declined a card, because that exchange happens on Stripe's hosted checkout page, outside Whizi's codebase. A sweep of both Whizi repos found no card declined or payment declined string of any kind, and the Stripe webhook handler carries no declined payment message. So there is no decline reason stored in your account, no retry button, and nothing for Whizi to override. The reason sits with your bank.

Whizi also has no message for a failed or past due renewal. No user-facing string for one exists in either repo, so if a renewal charge fails later you will not get a Whizi error explaining it. The one renewal adjacent notice that does exist is a push notification reading "Your subscription is no longer active." under the title "Whizi subscription updated", sent when a RevenueCat webhook syncs an account down to the free tier. That is the RevenueCat webhook path, so it is not a report of a Stripe renewal failing.

Whizi billing runs through Stripe, so which cards can pay at all is decided there rather than in Whizi. A Russian or Iranian card cannot complete registration. Ukraine, Kazakhstan, Turkey, Indonesia and India work end to end.