Mastercard assignment for two employees with same first 6 digits and same last 4 digits not created

There are two corporate cards (Mastercard CDF 3.0) with same first 6 digits and sae last 4 digits which should be assigned to two different employees. But, since the format of account number is same, it is not allowing to create two separate records. How to handle this? Is there a workaround or a way to fix this?