Area Code 781

About Area Code 781

Area code 781 is a geographic telephone area code assigned to Waltham, Massachusetts. It operates in the Eastern time zone and was first introduced in 1988. Split from 617. Eastern Massachusetts outside Boston. Overlay 339 (2001).

Within Massachusetts, area code 781 shares numbering capacity with 8 other area codes. The state's 7,100,960-person population (2023 Census Bureau estimate) is served by a combined 9 active codes, with 781 primarily responsible for the Waltham region. Massachusetts's state capital is Boston, and its largest city is Boston.

When you receive a call from a 781 number on your Caller ID, the call originated from a phone number assigned to the 781 area code — but be aware that Local Number Portability (in effect since 2003) means the caller could be physically located anywhere in the US or Canada. Area code 781 only confirms where the number was originally assigned.

Where is the 781 area code located?

Area code 781 is assigned to Waltham, Massachusetts, in the Eastern time zone. The state of Massachusetts uses 9 active area codes, and 781 is one of them. Calls placed from the 781 area code originate from numbers assigned by NANPA — the North American Numbering Plan Administrator — and the 781 prefix appears on Caller ID for both landline and wireless calls placed from this region.

The Eastern time zone observes Daylight Saving Time, shifting from UTC-5 to UTC-4 in summer. The local time shown above is always current, so you can quickly check whether it's a reasonable hour to call back.

What cities and counties use the 781 area code?

The 781 area code serves 10 notable cities, listed below in order of population. The largest city in the 781 territory is Boston (651,092 residents in Suffolk County).

• Boston, MA — 651,092 residents (37.3% of 781 numbers)
• Worcester, MA — 207,621 residents (11.9% of 781 numbers)
• Springfield, MA — 155,927 residents (8.9% of 781 numbers)
• Cambridge, MA — 118,927 residents (6.8% of 781 numbers)
• Lowell, MA — 114,790 residents (6.6% of 781 numbers)
• Brockton, MA — 105,451 residents (6% of 781 numbers)
• Quincy, MA — 101,728 residents (5.8% of 781 numbers)
• Lynn, MA — 101,993 residents (5.8% of 781 numbers)
• Fall River, MA — 94,449 residents (5.4% of 781 numbers)
• New Bedford, MA — 95,363 residents (5.5% of 781 numbers)

Phone number format in area code 781

All phone numbers within area code 781 follow the standard North American 10-digit format:(781) NXX-XXXX. The NXX is the central office prefix (also called an "exchange") and XXXX is the subscriber line number. For long-distance calls within the NANP, dial 1 + 781 + NXX + XXXX. From outside North America, dial your country's international access code, then 1 (the NANP country code), then the 10-digit number.

If you need to verify whether a specific 781 number is wireless, landline, or VoIP, you can use our reverse phone lookup tool. Be aware that number portability means the area code no longer guarantees the caller's physical location — only where the number was first assigned.

History of area code 781

Split from 617. Eastern Massachusetts outside Boston. Overlay 339 (2001).

The original 86 area codes were assigned by AT&T and Bell Labs in 1947 as part of the North American Numbering Plan. At the time, rotary-dial phones meant codes with lower digits (like 212 for NYC, 213 for LA, 312 for Chicago) were given to the largest cities because they took less time to dial. Today's area code assignments still reflect those early choices, even though touch-tone and cell phones made the original reason obsolete.

Is the 781 area code safe to answer?

Area code 781 itself is a normal geographic code with no elevated spam risk. That said, scammers can spoof any area code — including 781 — so if you don't recognize the full number, let it go to voicemail and verify the caller's identity before calling back.