Potomac Maryland Area Codes
3 area codes cover Potomac: 227, 240 and 301. A number carrying any of them is local to Potomac.
The codes covering Potomac
| Area code | Primarily serves | Shares ground with | In service |
|---|---|---|---|
| 227 | Baltimore | 240, 301 | 2023 |
| 240 | Baltimore | 227, 301 | 1997 |
| 301 | Baltimore | 227, 240 | 1947 |
A code in the “shares ground” column is an overlay: it covers the same territory rather than a different part of Potomac, which is why local calls there are dialled as ten digits.
Scope the codes matched to Potomac. Source geoinfo-dataset (full_dataset) ZIP→NPA (2018 snapshot) and LocalCallingGuide NPA list (2026-07 NPA list). Updated . Overlay relationships come from the numbering-plan authority; the place match is computed.
Which part of town has which code
We do not publish which of these codes covers which street or neighbourhood in Potomac, and we would rather say so than guess. Area codes are drawn around telephone rate centres, which follow neither municipal boundaries nor ZIP codes, and the per-ZIP telephone data we hold is a 2018 snapshot too noisy to split a city with. Where these codes overlay one another the question has no answer at all: they cover the same ground by design. Awaiting a current, clean-rights rate-centre boundary source.
ZIP codes for the same city
Postal geography is organised separately from telephone geography, so Potomac’s 2 ZIP codes do not map onto the codes above. They are listed in full, with the county each falls in, on the postal side of the site.
Nearby places with different codes
These are the closest places to Potomac whose area codes are not the same set. If you are near one of them, a local number may carry a code that is not on the list above.
| City | Distance | Their area codes |
|---|---|---|
| Hyattsville Maryland area codes | 13 mi | 227, 240, 301, 410, 443, 667 |
| Laurel Maryland area codes | 19 mi | 227, 240, 301, 410, 443, 667 |
| Columbia Maryland area codes | 22 mi | 227, 240, 301, 410, 443, 667 |
| Bowie Maryland area codes | 25 mi | 227, 240, 301, 410, 443, 667 |
| Mount Airy Maryland area codes | 25 mi | 227, 240, 301, 410, 443, 667 |
| Queen Anne Maryland area codes | 27 mi | 410, 443, 667 |
| Elkridge Maryland area codes | 27 mi | 227, 240, 301, 410, 443, 667 |
| Sykesville Maryland area codes | 28 mi | 410, 443, 667 |
Straight-line distance between place reference points, not driving distance.