---
title: "Area code 240: Maryland, United States"
url: "https://lookvalid.com/area-code/240.md"
canonical_url: "https://lookvalid.com/area-code/240"
last_updated: "2026-10-23"
type: "reference"
summary: "Area code 240 serves Maryland, United States. Number formats, numbering rules, a live phone validator and the other codes in Maryland."
---

# Area code 240: Maryland, United States

Area code 240 serves Maryland, United States. Number formats, numbering rules, a live phone validator and the other codes in Maryland.

NANPA lists 785 central office codes (prefixes) in use in area code 240, held by 41 holders across 63 rate centers.
Omnipoint Communications Cap Operations holds the most prefixes, 117 (15%). 93% of the prefixes are pooled, which means their thousands-blocks can belong to different companies.
The FCC unwanted-call data has 4,173 complaints on file for 3,070 numbers in 240, most often filed as "Unwanted Calls". These are consumer reports, not findings.

## Facts

- In service since: 1997-06-01
- Time zone: Eastern (E)
- Assigned overlays: 301 (1947-01-01), 227 (2023-06-14)
- Prefixes in use: 785
- Pooled prefixes: 727 (93%)
- Rate centers: 63
- Companies holding prefixes: 41
- Assignment dates on file: 2001-01-09 to 2023-07-25 (443 prefixes)
- ZIP codes in its places: 42

## Rate centers

| Rate center | Prefixes | Share |
| --- | --- | --- |
| WSHNGTNZN3 | 73 | 9% |
| WSHNGTNZN2 | 64 | 8% |
| WSNGTNZN10 | 54 | 7% |
| FREDERICK | 43 | 5% |
| GAITHERSBG | 40 | 5% |
| LAUREL236 | 39 | 5% |
| HAGERSTOWN | 33 | 4% |
| WSHNGTNZN4 | 30 | 4% |
| 55 other rate centers | 409 | 52% |

## Carriers

| Holder | Prefixes | Share |
| --- | --- | --- |
| Omnipoint Communications Cap Operations | 117 | 15% |
| Verizon Wireless | 85 | 11% |
| New Cingular Wireless PCS | 69 | 9% |
| Paetec Itel | 63 | 8% |
| Level 3 Communications | 59 | 8% |
| Onvoy | 56 | 7% |
| 35 other carriers | 336 | 43% |

A prefix holder is the company a code was assigned to, not necessarily a number's current carrier, because numbers can be ported to another company.

## History

- 1947-01-01: Area code 301, named as the parent of 240 in the NANPA report, was in service.
- 1997-06-01: Area code 240 went into service.

## Nearest area codes

The area codes closest to 240, measured between the centers of the ZIP code places they serve, are 571 (about 36 miles), 703 (about 36 miles), 443 (about 75 miles), 223 (about 76 miles) and 717 (about 76 miles).

## ZIP codes

42 ZIP codes fall in places that have a rate center in this area code. The places with the most are Frederick, MD (6 ZIP codes), Hagerstown, MD (6 ZIP codes) and Cumberland, MD (5 ZIP codes). A ZIP code and an area code are unrelated systems, so a ZIP code can sit in more than one area code and an area code spans many ZIP codes.

## Complaints on file

4,173 complaints for 3,070 numbers. Numbers whose latest complaint falls in each year:

- 2023: 210
- 2024: 234
- 2025: 136

## Questions

### Where is area code 240?

NANPA assigns area code 240 to Maryland, United States.

### In which state does area code 240 sit?

Maryland. 240 is one of 6 area codes the NANPA table assigns to the state.

### Which places does area code 240 cover?

The places with the most ZIP codes among the rate centers in 240 are Frederick, MD, Hagerstown, MD and Cumberland, MD. The rate center list on this page shows all of them.

### Who owns area code 240?

NANPA assigns area codes. Within 240, Omnipoint Communications Cap Operations holds the most prefixes, 117 prefixes or 15%.

### Which time zone does 240 use?

The NANPA NPA report lists the time zone for 240 as Eastern (E).

### What year did 240 enter service?

The NANPA NPA report gives an in-service date of 1997-06-01, so 240 has been in use since 1997.

### Does area code 240 have an overlay?

Yes. 301 (in service 1947-01-01) and 227 (in service 2023-06-14) share the same area with 240, so numbers from all of them are local to each other.

### Which area codes are nearest to 240?

The area codes closest to 240, measured between the centers of the ZIP code places they serve, are 571 (about 36 miles), 703 (about 36 miles), 443 (about 75 miles), 223 (about 76 miles) and 717 (about 76 miles).

### How many prefixes does area code 240 have?

NANPA's report dated 2026-10-17 lists 785 prefixes in service in 240, spread over 63 rate centers and 41 holders.

### Are there complaints about 240 numbers?

The FCC data on file has 4,173 complaints for 3,070 numbers in 240. They are unverified consumer reports. A number with no complaints on file is not proven safe.

Sources: NANPA central office code report dated 2026-10-17; NANPA NPA report dated 2026-10-18; FCC unwanted-call complaints, data fetched 2026-10-17; ZIP code places from GeoNames (CC BY 4.0).