ERR_PAYMENT_DECLINED on Stripe: Payment declined. Root cause: The payment transaction was declined by the card issuer or payment processor. Common causes include insufficient funds, the card being flagged for suspected fraud, the card's daily or transaction limit being exceeded, the billing address not matching the card on file, or the card being expired or blocked for international transactions. Step 1: Check card details. Verify card information Step 2: Check balance. Verify sufficient funds Step 3: Try different card. Use alternative payment Step 4: Contact bank. Check with card issuer