Massachusetts Address Generator

New England's postal codes were allocated as a tight sequence, and the pattern is unusually clean: Massachusetts takes 010 to 027, Rhode Island 028 to 029, New Hampshire 030 to 038, Maine 039 to 049, Vermont 050 to 059, and Connecticut 060 to 069. Six states in sixty prefixes, in order.

Massachusetts breaks it exactly once. Its prefix set is 010 through 027 plus a single outlier at 055 — 05501 and 05544, both Andover, Massachusetts, in Essex County, sitting inside Vermont's block. They are Internal Revenue Service facility codes, and they are real: mail addressed to 05501 goes to Andover, not to Vermont.

Two rules fail on that one prefix, in opposite directions. A range check that says 010–027 is Massachusetts rejects a genuine Massachusetts address. A range check that says 050–059 is Vermont accepts one and files it in the wrong state — which is worse, because nothing errors. It is a single-facility code rather than a residential one, so a delivery-type filter catches it, but a state-mapping table will not unless somebody put it there deliberately.

The rest of the state is dense rather than complicated: 685 codes across 14 counties, about 49 codes per county — the second-highest ratio in the country after the District of Columbia. The largest prefix by code count is 010 around Chicopee in the western half, not 021 around Boston, which is the usual reminder that a sorting facility's size follows its territory rather than its population.

Boston itself carries the other Massachusetts complication, and it is the same one New York has: the Postal Service files parts of the city under neighbourhood names rather than under Boston. Allston, Brighton, Charlestown, Dorchester, Jamaica Plain, Roslindale and West Roxbury are all inside the city limits and all appear as their own place names in the postal file. So a Boston resident who writes their neighbourhood is correct, one who writes Boston is also correct, and a validator that insists on a canonical city name rejects one of them. Accept what the customer types and standardise only at the carrier boundary.

Random Massachusetts phone numbers here use the state's real area codes — 617, 508, 413 and 978 — with the 555-01XX line range the North American Numbering Plan reserves for fiction, so a number such as (617) 555-0165 passes format and area-code checks yet can never ring anyone. Every profile this page generates carries one that agrees with its Massachusetts address; for a batch of numbers on their own, the random Massachusetts phone number generator draws from the same range with any US area code.

Three examples in the reserved range: (617) 555-0165, (508) 555-0174, (413) 555-0116. Area codes are geographic, so a Massachusetts address paired with a non-MA area code fails the consistency check that fraud systems and good validators run — which is why this page pins both to Massachusetts. How area codes are assigned, and why the 555 block exists, are covered in how US area codes work and why fake phone numbers start with 555.