First, try clearing your browser's cache and deleting your cookies. See the TurboTax Help articles How to clear your cache and How do I delete cookies? for guidance.
If that doesn’t remedy your situation, there may be a mismatch between the information you've entered and what's on file with your credit card company.
See the TurboTax Help article Error: "We are having trouble validating your credit card, please try again" for guidance.
