Winthrop, MA — rate center
- State
- Massachusetts
- Active prefixes
- 11
- Carriers
- 9
- Pooled prefixes
- 10
- LATA
- 128
- Metro area
- Boston-Cambridge-Newton, MA-NH MSA
Winthrop is a telephone rate center in Massachusetts served by area codes 617, 857. A rate center is the locality the phone industry uses to anchor numbers for billing; every prefix listed below is registered here.
The rate center currently carries 11 working prefixes, held by 9 different carriers. Pooling applies to 10 of them — individual thousands-blocks may belong to different companies.
The rate center belongs to the Boston-Cambridge-Newton, MA-NH Metropolitan Statistical Area. Routing-wise it sits in LATA 128.
Because 617, 857 all serve this territory, two Winthrop numbers can look completely different while being neighbors — check the prefix, not just the area code.
A Winthrop prefix on caller ID is a starting point, not proof of origin — numbers travel with their owners and displays can be spoofed. Use official callback numbers for anything sensitive.
Prefixes anchored to Winthrop
| Prefix | Code holder | Pooled |
|---|---|---|
| 617-207 | COMCAST IP PHONE, LLC | Yes |
| 617-329 | RCN TELECOM SERVICES, INC. - MA | Yes |
| 617-539 | VERIZON NEW ENGLAND INC. | Yes |
| 617-841 | LEVEL 3 COMMUNICATIONS, LLC - MA | Yes |
| 617-846 | VERIZON NEW ENGLAND INC. | No |
FAQ
What area code is Winthrop, MA?
Winthrop is served by 2 area codes — 617, 857 — which overlay the same territory.
How many prefixes does Winthrop have?
11 active NXX prefixes are anchored to this rate center in NANPA records, held by 9 carriers.
Is a call from a Winthrop prefix really from Winthrop?
Not necessarily. The prefix marks where the number block was issued; porting, VoIP and spoofing all detach calls from that geography.