Bank of the West Routing Number: BMO Transition Guide

What is the Bank of the West routing number?

Bank of the West historically used routing number 121100782 for accounts in California and other western states. However, Bank of the West was acquired by BMO (Bank of Montreal) in February 2023, and its branches were rebranded under the BMO name by September 2023.

During and after the transition, the legacy routing number 121100782 may still appear on older checks and documents. BMO has been migrating former Bank of the West customers to BMO routing numbers, so your current routing number depends on whether your account has been fully converted.

BMO acquisition and routing number changes

BMO Financial Group completed its $16.3 billion acquisition of Bank of the West in early 2023, making it one of the largest bank mergers in recent years. All Bank of the West branches were converted to BMO branches, and customers received new BMO account details including updated routing numbers.

If you were a Bank of the West customer, check your BMO online banking portal or contact BMO directly to confirm your current routing number. BMO uses routing number 071025661 for many accounts, but your specific number may vary by state.

How to find your current routing number

Log into the BMO digital banking platform to find your updated routing number. Former Bank of the West customers were migrated to BMO systems, and your new routing number is displayed in the account details section of the BMO app or website.

You can also find your routing number on BMO-issued checks (the nine-digit number at the bottom left), by calling BMO customer service, or by visiting a local BMO branch. Do not rely on the old Bank of the West routing number for new transactions.

Setting up direct deposit and transfers

When setting up direct deposit or ACH transfers, always use your current BMO routing number rather than the legacy Bank of the West number. While some payment systems may still route transactions using the old number during a grace period, this is not guaranteed long-term.

For wire transfers, BMO may use a different routing number than your ACH routing number. Confirm both your ACH and wire routing numbers through BMO online banking before initiating any transfers.

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