BMO Harris Bank has different routing numbers depending on the type of transaction and the location of the account. Generally, for customers in Illinois, the routing number is 071000048, while other states may have different numbers. It is essential to verify the specific routing number for your account based on where it was opened and the type of transaction you intend to conduct. For the most accurate and up-to-date information, customers can refer to their checks or account statements, or they can visit the official BMO website. There you will find the correct routing number suitable for your needs. If you have additional questions about this topic, the website may also have helpful resources.