Destination code, address code, postcode or address code refers to the barcode that various postal companies print on letters and postcards. The destination code is applied to the item at the first mail centre it passes through. This enables faster machine forwarding and sorting.
Encoding/Decoding
German Post uses two different types of coding, 5-bit coding and 4-bit coding. The table opposite shows the coding of each digit. Each bit of the code corresponds to a numerical value. The numerical values of the set bits of the code are added together, their sum is the number that has been decoded, whereby there is an exception in both encodings: In 5-bit coding, the sum (7+4)=11 represents the digit “zero”; in 4-bit coding, the sum (8+2)=10 represents the digit “seven”. This means that with 5-bit coding, exactly 2 bits are always set and 3 are not set and with 4-bit coding, a maximum of two bits are set and at least two are not set. 10 of the 11 such coding dash patterns are used, 8+4=12 is not used.
Formats
| Linear-Code 30, 4 digits | This coding was used from 1978 to 1995. It consists of 5 segments: The 4 digits of the postcode or a postcode-like internal company code (IKZ) and a check digit, each separated by a dash. |
| Linear-Code 36, 5 digits | Since 1995, the five-digit postcodes have been encoded together with an additional check digit in a 36-digit linear code. To this day, the target code for five-digit postcodes is always printed on letters and postcards if the machine is unable to recognise the postcode. In this case, a photo of the letter is shown to an employee to type in the postcode on the screen. |
| Linear-Code 69, 11 digits | Codes for the house number (12+3 digits) and street number (12+3 digits) have been added. These components are coded with one 4-bit binary number per decimal digit and one separator bit. Several digits that form a unit are coded from right to left. |
| Linear-Code 80,13 digits | A patent application was filed in 2003 for the combination of the previously coded address (69 digits) on the right-hand edge of the consignment and the payment protection code (11 digits) to the left of it. The charge protection code contains information about the franking and any irregularities in the franking process. |