21231 ZIP Code

Extra Details of ZIP Code 21231

Data: State Statistics Office | Updated on: May 04, 2026

How to write a U.S. envelope?

The first step is to write the recipient address:
First, you need to fill in the recipient's mailing information in the center of the envelope. The first line is also the recipient's name. When writing the recipient's name, pay attention to the title, and write the person's title and name in the middle of the envelope. On the second line, write the recipient's full address, including any associated apartment or suite numbers. The more detailed the better. The third line writes the recipient's city, state, and zip code, this information is the last line of the address.

The second step is to write the reply address:
The return address is three lines, the first line will be the sender's name. The second line writes the sender's detailed address, including the street address, please remember to write the house number. On the third line write your city, state abbr, and zip code.

Finally, don't forget to stick the stamp on the right top corner. Otherwise, the letter will not go into the delivery process.

Population and Employment

Location of Zip Code 21231

On this map you can see exactly where postcodes are located within Germany.

Gender & Age Statistics

21231 Demographics

21231 Income

Online Business Directory

Whether you're looking for hotels, hairdressers, doctors or lawyers in Baltimore, MD. You can find these phone numbers in our phone book. With us, you can easily book a restaurant or hotel in your location. You can also find reputable real estate agents and insurance agents. Everything you need is easily accessible here!

Schools Serving Baltimore

Library Baltimore

Museum Baltimore

Hospital Baltimore

University Baltimore