BMO headquarters in the United States is BMO Tower at 320 S Canal Street, Chicago, IL 60606 — and if you are still searching for “BMO Harris headquarters,” you are looking for the same building. The bank retired the BMO Harris name in 2023 and now operates as BMO Bank N.A., a subsidiary of Toronto-based Bank of Montreal. Below you will find the current U.S. corporate office address, the parent company’s head office in Toronto, the official customer service phone numbers, the correct mailing addresses for complaints and loan correspondence, and the escalation steps that actually work when the front line cannot solve your problem.
| U.S. headquarters | BMO Tower, 320 S Canal Street, Chicago, IL 60606, United States |
| Parent company head office | Bank of Montreal, 100 King Street West, 1 First Canadian Place, Toronto, Ontario M5X 1A1, Canada |
| Former U.S. headquarters | 111 West Monroe Street, Chicago, IL 60603 (Harris Bank home for 110 years; vacated in 2022) |
| Customer service phone number | 1-888-340-2265 (7 a.m.–11 p.m. CT weekdays, 8 a.m.–10 p.m. weekends) |
| Credit cards | 1-855-825-9237 (24/7) |
| Mortgage applications | 1-888-482-3781 (Mon–Thu 8 a.m.–7 p.m., Fri 8 a.m.–6 p.m., Sat 8 a.m.–1 p.m. CT) |
BMO Headquarters Location and Contact Information
BMO’s U.S. operations — BMO Financial Corp. and its bank subsidiary BMO Bank N.A. — are headquartered at BMO Tower, 320 S Canal Street, Chicago, IL 60606. The 50-story tower next to Union Station opened in spring 2022 and, in the bank’s own words, “will serve as BMO’s U.S. Headquarters for decades to come.” The move consolidated more than 3,000 Chicago employees who had been spread across the Loop, including the historic Harris Bank complex at 111 West Monroe Street that had served as headquarters for 110 years. If an older directory still lists 111 W Monroe as the BMO Harris headquarters, that information is out of date.
The Chicago office is the head office for the U.S. bank only. The ultimate parent, Bank of Montreal (BMO Financial Group), was founded in Montreal in 1817 and runs its executive offices from 100 King Street West, 1 First Canadian Place, Toronto, Ontario M5X 1A1. Keep in mind that neither address is a customer-service location: BMO Tower houses executives and corporate staff, not a walk-in service desk, and you cannot make deposits or payments there. For everyday banking, use the branch locator on bmo.com or the phone lines below.
Phone Contacts
BMO publishes a single main number for most banking needs plus dedicated lines for cards and mortgages. All of the numbers below come from the bank’s official U.S. contact page; hours are Central Time:
- Personal banking and general inquiries: 1-888-340-2265 — customer care team 7 a.m.–11 p.m. CT Monday to Friday, 8 a.m.–10 p.m. Saturday and Sunday; password resets, debit card activation and lost/stolen debit card reports are handled 24 hours a day
- Outside the U.S.: 1-847-238-2265
- Credit cards (BMO Platinum, Platinum Rewards, Cash Back): 1-855-825-9237 — 24/7; 1-262-780-8658 from outside the U.S.
- Business credit cards (BMO Business Platinum): 1-855-825-9231 — 24/7
- Diners Club U.S. cards: 1-800-234-6377 — 24/7
- Mortgage applications and refinancing: 1-888-482-3781 — Mon–Thu 8 a.m.–7 p.m., Fri 8 a.m.–6 p.m., Sat 8 a.m.–1 p.m. CT
- Existing mortgage servicing questions: 1-888-340-2265
- Online and mobile banking support: 1-888-340-2265 — 7 a.m.–11 p.m. CT weekdays, 8 a.m.–10 p.m. weekends
- Customer complaint resolution: 1-888-340-2265 — 8 a.m.–10 p.m. CT weekdays, 8 a.m.–5 p.m. weekends
- Small business banking: 1-888-340-2265 — 8 a.m.–7 p.m. CT weekdays, 8 a.m.–5 p.m. Saturday
- BMO Investment Services accounts: 1-877-225-3863
Customer Service and Support Channels
Phone is not the only way in. Signed-in customers can open BMO Assist inside BMO Digital Banking and choose “Chat with a Banker” to reach a live representative over a secure connection during business hours — the safest channel for anything that involves account numbers, since BMO, like every bank, warns customers never to send account details by regular email. The same app handles card locks, replacement cards and dispute requests without a hold queue.
On social media, BMO’s U.S. team answers public questions through @BMO_US on X and the BMO U.S. page on Facebook, but will always move you to a private channel before discussing an account. If you prefer face-to-face help, BMO operates roughly 840 U.S. branches (the bank calls them financial centers) after selling 138 locations in September 2026, with new centers opening across California and Arizona. One practical tip: the customer care line opens at 7 a.m. CT on weekdays, and the first hour or two after opening is consistently the quietest time to call.
Mailing Addresses for Complaints and Correspondence
Writing to the corporate tower is the most common mistake customers make — letters sent to 320 S Canal Street get forwarded, and the delay costs you weeks. BMO publishes specific addresses for written complaints and loan correspondence on its contact page. These are the ones that matter:
| Written complaints and escalations | BMO Bank Customer Advocacy Support and Escalation Team, 1200 E. Warrenville Road, Naperville, IL 60563 |
| Mortgage servicing errors and information requests | BMO Bank N.A., Attention: NOE1290, 1 Corporate Drive, Suite 360, Lake Zurich, IL 60047-8945 |
| Auto loan automatic-debit forms | BMO, Loan Maintenance, P.O. Box 2045, Milwaukee, WI 53201 |
| U.S. corporate office (no payments) | BMO Financial Corp., 320 S Canal Street, Chicago, IL 60606 |
| Parent company head office | Bank of Montreal, 100 King Street West, 1 First Canadian Place, Toronto, ON M5X 1A1, Canada |
Which Address and Routing Number Go on Direct Deposit Forms?
Direct deposit and wire forms ask for a routing number rather than a street address. BMO uses a single routing number for all U.S. personal bank accounts: 071025661, published on the official contact page. When a form insists on a bank address, the legal entity is BMO Bank N.A., a national bank headquartered in Chicago. BMO’s U.S. holding company and bank are both based in Illinois, and you can confirm the registration of any BMO entity doing business in the state through the Illinois Secretary of State — our Illinois business search guide explains how.
Company Background
Bank of Montreal is Canada’s oldest bank, established in Montreal in 1817. Its American story begins in Chicago in 1882, when Norman Wait Harris founded the bond house N.W. Harris & Co., the forerunner of Harris Trust and Savings Bank. In 1984 Bank of Montreal bought Harris — the first acquisition of a U.S. bank by a Canadian financial institution — and in 2011 it added Milwaukee-based Marshall & Ilsley, creating BMO Harris Bank, one of the largest banks in the Midwest.
The biggest change came on February 1, 2023, when BMO completed its acquisition of Bank of the West from BNP Paribas, adding 1.8 million customers and more than 500 branches in California and other western states. Later that year the bank retired the BMO Harris brand, converted Bank of the West customers over Labor Day weekend, and began doing business everywhere as simply BMO, with the legal name BMO Bank N.A. Today BMO Financial Group is the eighth-largest bank in North America by assets, with total assets of about $1.5 trillion (CAD) as of July 31, 2026, roughly 13 million clients and about 53,000 employees company-wide, trading on the New York and Toronto stock exchanges under the ticker BMO.
The U.S. footprint is still being reshaped. BMO’s own branch list counted 982 open U.S. branches as of April 1, 2026; on September 4, 2026 the bank completed the sale of 138 branches in the Dakotas, Wyoming, Nebraska, Kansas, Missouri, Oklahoma, Idaho and parts of Minnesota, Oregon and Illinois to First-Citizens Bank, leaving roughly 840 locations. At the same time it announced more than 130 new financial centers in California and about 15 in Arizona over five years, a bet on the markets it picked up with Bank of the West.
Leadership
Darryl White has been Chief Executive Officer of BMO Financial Group, the Toronto-based parent, since 2017. The U.S. business is run by Darrel Hackett, who became U.S. CEO of BMO Financial Group on June 1, 2023 and also serves as Chief Executive Officer of BMO Financial Corp. and President and CEO of BMO Bank N.A., based at the Chicago headquarters. In July 2025 BMO added Aron Levine, a longtime Bank of America executive, as Group Head and President, BMO U.S., reporting to Hackett and White.
Key Office Locations
Chicago is the U.S. headquarters, but BMO’s operations are spread across several hubs. Milwaukee hosts the Wisconsin headquarters in a second BMO Tower at 790 N Water Street, opened in 2020 on the former Marshall & Ilsley site. Naperville, Illinois is home to the customer advocacy and escalation team, and Lake Zurich, Illinois handles mortgage servicing correspondence. In California, the legacy Bank of the West network gives BMO more than 220 financial centers, its largest presence outside the Midwest. North of the border, Toronto’s First Canadian Place holds the group executive offices, while Montreal remains the bank’s founding city and legal head office.
Dealing with Customer Complaints
Start with the standard channels: call 1-888-340-2265, which doubles as BMO’s customer complaint resolution line, or use the secure chat in BMO Digital Banking, and keep a record of the date, the representative’s name and any case number. If the front line cannot resolve it, put the complaint in writing to the BMO Bank Customer Advocacy Support and Escalation Team, 1200 E. Warrenville Road, Naperville, IL 60563 — this is the address BMO itself designates for escalations, and letters sent there are logged and assigned rather than forwarded from the corporate tower.
Because BMO Bank N.A. is a national bank, you also have a step most companies’ customers do not. Its primary federal regulator is the Office of the Comptroller of the Currency, which runs a dedicated consumer assistance site at HelpWithMyBank.gov (1-800-613-6743). You can also file with the Consumer Financial Protection Bureau; banks are required to respond to CFPB complaints, typically within 15 days, and this route has a strong track record of unsticking stalled disputes. For unresolved money disputes, small-claims court remains an option of last resort.
Summary
BMO’s U.S. headquarters — the address people still search for as BMO Harris headquarters — is BMO Tower, 320 S Canal Street, Chicago, IL 60606, with the parent Bank of Montreal based at First Canadian Place in Toronto. Almost everything a customer needs, though, happens elsewhere: 1-888-340-2265 for customer service, 1-855-825-9237 for credit cards, the Naperville address for written complaints, and the OCC or CFPB when escalation is needed. Looking for another company’s corporate contacts? Browse our other headquarters guides.
Frequently Asked Questions
Where is BMO’s headquarters located?
BMO’s U.S. headquarters is BMO Tower, 320 S Canal Street, Chicago, IL 60606. The parent company, Bank of Montreal, is headquartered at 100 King Street West, First Canadian Place, Toronto, Ontario M5X 1A1, Canada.
Where is the BMO Harris headquarters?
BMO Harris Bank was renamed BMO Bank N.A. in 2023, and its headquarters is the same Chicago office: BMO Tower, 320 S Canal Street. The old Harris Bank headquarters at 111 West Monroe Street was vacated in 2022.
What is BMO’s customer service phone number?
Call 1-888-340-2265 for personal banking and general inquiries (7 a.m.–11 p.m. CT weekdays, 8 a.m.–10 p.m. weekends). Credit card holders can call 1-855-825-9237 around the clock.
Who is the CEO of BMO?
Darryl White is CEO of BMO Financial Group, the Toronto-based parent. Darrel Hackett is U.S. CEO and President and CEO of BMO Bank N.A., leading the business from the Chicago headquarters.
Who owns BMO Bank?
BMO Bank N.A. is wholly owned, through BMO Financial Corp., by Bank of Montreal, a publicly traded Canadian bank listed on the New York and Toronto stock exchanges under the ticker BMO.
How do I file a complaint against BMO?
Call 1-888-340-2265 first, then write to the BMO Bank Customer Advocacy Support and Escalation Team, 1200 E. Warrenville Road, Naperville, IL 60563. If that fails, file with the OCC at HelpWithMyBank.gov or with the CFPB at consumerfinance.gov.