An “invalid account number” would indicate that the credit card number is not entered correctly, or the account is not activated.
Please make sure that the card is active and re-enter the numbers without any spaces. If this is a purchasing card, you may need the address to match exactly depending on the card issuer restrictions.
It could be something such as:
- Purchase amount exceeds available credit limit
- Card Verification Value does not match
- Address verification does not match
- International transaction
- Unusual activity than your regular purchases
- Multiple attempts
Try to use a different credit card, or contact the card-issuer to advise that you are trying to make a purchase in the amount of $___ to the Association for Financial Professionals in Maryland, United States.