PEnnsylvania 6-5000

PEnnsylvania 6-5000 is a telephone number in New York City, written in the 2L+5N (two letters, five numbers) format that was common in the largest US cities from approximately 1930 into the 1960s. The named Pennsylvania exchange served the area around Penn Station in New York. The two letters, PE, stand for the numbers 7 and 3, making the phone number 736-5000, not including the area code 212 for Manhattan.

The number is best known from the 1940 hit song "PEnnsylvania 6-5000", a swing jazz and pop standard recorded by the Glenn Miller Orchestra. Its owner, the Hotel Pennsylvania, claims it to be the oldest continuing telephone number in New York City. While the hotel opened in 1919, the exact age of the telephone number and the veracity of the hotel's claim are unknown.

At the time of Glenn Miller's popular network radio broadcasts, most local telephone calls in large cities were being dialed directly. All intercity calls required the operator. There were no area codes. The length of local numbers varied widely; four or five digits was more than enough for a small city with a single central office, while separate central offices served individual neighborhoods of larger cities.

In large cities, each central office had one or more telephone exchange names. In the 2L+5N system, used only in large cities, a seven-digit local number was dialed as the first two letters of the exchange name (PE for "PEnnsylvania", the exchange serving the area around Penn Station) and five digits.

The telephone numbering plans implemented by telephone companies did not follow any standard practice until the North American Numbering Plan was created by AT&T in 1947. The first automated dial exchanges in the Bell System were deployed in 1919. When seven-digit telephone numbers were first assigned in New York in 1920, the three-letter four-number (3L-4N) system had represented the number in the format PENnsylvania 5000. Similar systems were used in Boston, Chicago, and Philadelphia. By 1930, the 3L-4N system was changed to a 2L–5N system, using two letters and five digits, and PEN-5000 became PE6-5000, much like the BUTterfield central office became BUtterfield 8.

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