Is MFSMUS33 a valid SWIFT code?

Yes. MFSMUS33 has the right format and is in our directory for MASSACHUSETTS FINANCIAL SERVICES COMPANY, BOSTON. Confirm with the beneficiary that it is the bank that holds their account.

What is the difference between MFSMUS33 and MFSMUS33XXX?

None. MFSMUS33 is the 8-character form of MFSMUS33XXX; XXX at the end means the head office. Either works.

SWIFT/BIC · United States

MFSMUS33

MASSACHUSETTS FINANCIAL SERVICES COMPANY · Head office · BOSTON

Code details

SWIFT/BIC: MFSMUS33 (MFSMUS33XXX)
Institution: MASSACHUSETTS FINANCIAL SERVICES COMPANY
Office: Head office
Branch code: XXX · head office
Address: 111 HUNTINGTON AVENUE, 02199 BOSTON
City: BOSTON
Country: United States

What MFSMUS33 means

MFSMUS33XXX

MFSMBank code
Four letters chosen by the institution.
USCountry code
United States (ISO 3166)
33Location code
Where the institution sits on the SWIFT network. A 1 in second place marks a passive participant.
XXXBranch code
XXX, or nothing at all, means the head office.

Paying an account at this bank

United States does not use IBAN: send the beneficiary’s local account number with this code. Check an IBAN →

Questions

Is MFSMUS33 a valid SWIFT code?: Yes. MFSMUS33 has the right format and is in our directory for MASSACHUSETTS FINANCIAL SERVICES COMPANY, BOSTON. Confirm with the beneficiary that it is the bank that holds their account.
What is the difference between MFSMUS33 and MFSMUS33XXX?: None. MFSMUS33 is the 8-character form of MFSMUS33XXX; XXX at the end means the head office. Either works.

Sending to MFSMUS33?

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About this data

Codes are checked against our directory of banks on TrillioniPay corridors. Always confirm the code with the beneficiary’s bank before sending a payment. Last updated: 23 September 2026.

Institution names and addresses: Global Legal Entity Identifier Foundation (GLEIF) LEI data, available under CC0. The address is the legal entity’s registered or head-office address, which can differ from the office SWIFT lists.

SWIFT © and database rights August 2026. All rights reserved. This Mapping Table has been developed by SWIFT. Any use of the Mapping Table, in whole or in part, is subject to the BIC/LEI Mapping Table License Agreement as published with the Mapping Table available on GLEIF's website. The Mapping Table is updated monthly. For the latest BIC information and updates, always refer to www.swift.com/bic .