M&T Bank Routing Number: Navigating a Century of Mergers

M&T Bank

M&T Bank's primary routing number is 022000046, tied to its roots in Buffalo, New York, where the bank was founded as Manufacturers and Traders Trust Company in 1856. The 0220 prefix reflects the Federal Reserve Bank of New York's Buffalo processing center - a detail that has persisted for over a century even as M&T expanded across the Northeast.

Today M&T operates more than 1,000 branches across New York, Maryland, New Jersey, Pennsylvania, Delaware, Connecticut, Vermont, West Virginia, Virginia, and Washington, D.C. For most customers, 022000046 is the correct routing number, but the bank's acquisition history means some accounts still carry routing numbers from absorbed institutions.

The People

In April 2022, M&T completed its $7.6 billion acquisition of People's United Bank, a 180-year-old institution headquartered in Bridgeport, Connecticut. The merger added over 400 branches and roughly $63 billion in assets. People's United customers were migrated to M&T systems over the following months, and most received new M&T account and routing numbers in the process.

However, migration timelines vary. Some former People's United customers retained their original routing number (221172186) during a transition period. If you were a People's United customer, check your M&T online banking portal to confirm whether your routing number has been updated to 022000046 or if you are still on a legacy number.

When an acquisition changes your routing number - and when it does not

Bank acquisitions do not always trigger immediate routing number changes. When M&T acquired Provident Bank in 2009 and Wilmington Trust in 2011, legacy routing numbers continued to work for years. The acquiring bank typically maintains the old routing numbers in parallel until a full systems conversion forces the cutover. During this window, both the old and new routing numbers may work for incoming transactions, but only one is officially assigned to your account.

The safest practice after any bank merger is to log into your online banking, confirm the routing number displayed on your account, and update it with employers, billers, and anyone who sends you payments. Failing to update can result in delayed or returned ACH transactions once the legacy routing number is eventually retired.

M&T Bank wire transfer and international details

For domestic wire transfers, M&T Bank uses routing number 022000046 - the same as its primary ACH number. The SWIFT code for incoming international wires is MANTUS33. M&T charges $30 for outgoing domestic wires and $45 for international wires, with cutoff times typically at 4:00 PM ET for same-day processing.

M&T also supports Zelle for person-to-person payments and offers a commercial banking platform with batch ACH origination for business clients, both of which reference the same primary routing number.

How Slash eliminates the routing number confusion that follows bank mergers

Every bank merger creates a period of uncertainty: which routing number is active, whether old numbers still work, and when to update payroll and vendor records. Slash sidesteps this entirely with a single, stable account built for businesses. No legacy systems, no migration windows, no guessing. Just one account with clear routing details, real-time transaction visibility, and financial tools designed for modern operations.