Topic guide
Crypto card payment issues
Troubleshoot failed payments, recurring charges, billing addresses, 3DS, refunds, and point-of-sale payments.
5 published articles
- Payment failures
- Recurring charges
- Billing addresses
- Refunds and disputes
Latest publication
What Is a BIN?
A BIN is an issuer identification number used to identify the bank, card network, and card tier associated with a payment card. This article explains the six-digit BIN structure, the MII industry identifier, the ISO allocation mechanism, the history of UnionPay's 62-standard cards, and the issue of U Cards using credit or corporate-card BINs to bypass KYC.
More articles
Why Did My U Card Payment Fail? A Complete Troubleshooting Guide
U Card payment failures can happen for many reasons, including insufficient balance, card permission settings, 3DS verification, and merchant restrictions. This article provides a complete troubleshooting guide to help users identify the issue step by step and solve it.
Why Does a Card With Remaining Balance Still Fail to Pay?
A U-card account can have funds and still fail at payment. The reason may lie not in the balance itself, but in available balance, pre-authorization, limits, permissions, billing address, merchant restrictions, and other parts of the payment chain. This article walks through the payment flow step by step and provides practical fixes.
Common Reasons U-Card Transactions Are Declined
Common reasons U-Card transactions are declined include insufficient balance, abnormal card status, billing address mismatches, merchant restrictions, failed 3DS authentication, and risk-control blocks. This article explains 13 categories of causes and troubleshooting methods to help users quickly identify the problem.
What to Do When Your U Card Online Payment Fails
Common causes of U Card online payment failures include insufficient balance, card permission settings, incomplete 3DS verification, and merchant risk controls. This article provides a systematic troubleshooting process to help users quickly identify and resolve the problem.