Postnet


Postnet is a fixed width and height barcode that is used widely by the U.S. Postal Service. It encodes numeric digits by using 5 bars and 4 spaces. The bars have two different bar heights, short and tall.

ConnectCode Postnet Font

The list below illustrates the font that is supplied for Postnet.

  • CCodePostnet (Font Size 9)
Note - Postnet is a fixed size barcode that has specific width and height. When using this font, set the Font Size to 9 to adhere to the industry size specifications.


Postnet Character Mappings

All characters supported by the barcode is as shown below. All of them have a simple and direct mapping.

Data Character Barcode Font Character Value
Start Character'{' 
Stop Character'}' 
'0''0'0
'1''1'1
'2''2'2
'3''3'3
'4''4'4
'5''5'5
'6''6'6
'7''7'7
'8''8'8
'9''9'9



Postnet Check Character

For example, the check digit for the data string "12345" is calculated as follows.

Data 1 2 3 4 5
Sum : 1 + 2 + 3 + 4 + 5 = 15
If Sum Modulo 10 equals 0, the result is 0. Otherwise the result is 10 - (Sum Modulo 10)
Modulo 10 : 10 - (15 % 10) = 5
Data to be encoded 123455
Add Start/Stop characters {123455}


The characters "{123455}" can then be keyed in to the text editor with the appropriate font selected to generate a Postnet barcode with check digit.

ConnectCode Postnet Barcode Font

For example, to encode the data "12345", you can key in the following in your text editor and choose the Postnet barcode font.

Input (Into the Encoder or Visual Basic formulas): 12345

Manual Input: {123455}

Output:



The last digit '5' is the check digit. See the Calculation of the Postnet Check Digit section for more information.

For example, to encode the data "123456789", you can key in the following in your text editor and choose the I2of5 barcode font. As I2of5 barcode only allow even number of numeric digits, the above data should be treated as "056789".

Input (Into the Encoder or Visual Basic formulas): 123456789

Manual Input: {1234567895}

Output:



The last digit '5' is the check digit. See the Calculation of the Postnet Check Digit section for more information.

If you are using the Encoder, it will automatically put in the start/stop characters for you and add in the check character for you.