Chapter 2. Zero-Compressed UPC ⇒ UPC-E

Abstract

To allow the use of UPC barcodes on smaller packages where a full 12-digit barcode may not fit, a 'zero-compressed' version of UPC was developed called UPC-E.

This symbology differs from UPC-A in that it only uses a 6-digit code, does not use middle guard bars, and the end bit pattern (E) becomes 010101.

The way in which a 6-digit UPC-E relates to a 12-digit UPC-A is determined by the last (right-hand most) digit. With the manufacturer code represented by X's, and product code by N's then:

Last digit	UPC-E equivalent is	UPC-A equivalent is
0	XXNNN0	0XX000-00NNN + check
1	XXNNN1	0XX100-00NNN + check
2	XXNNN2	0XX200-00NNN + check
3	XXXNN3	0XXX00-000NN + check
4	XXXXN4	0XXXX0-0000N + check
5	XXXXX5	0XXXXX-00005 + check
6	XXXXX6	0XXXXX-00006 + check
7	XXXXX7	0XXXXX-00007 + check
8	XXXXX8	0XXXXX-00008 + check
9	XXXXX9	0XXXXX-00009 + check

For example a UPC-E barcode with the number 654321 would expand to the UPC-A 065100004327. You can convert UPC-E back to UPC-A using this web utility.

UPC-E check digits are calculated using this expanded string in the same way as used by UPC-A. The resulting check digit is not added to the barcode, however, but is encoded by manipulating the parity of the six digits which are present in the UPC-E - as shown in the following tables:

Check digit	Parity pattern
0	EEEOOO
1	EEOEOO
2	EEOOEO
3	EEOOOE
4	EOEEOO
5	EOOEEO
6	EOOOEE
7	EOEOEO
8	EOEOOE
9	EOOEOE

Digit to be encoded	Odd parity pattern	Even parity pattern
0	3-2-1-1	1-1-2-3
1	2-2-2-1	1-2-2-2
2	2-1-2-2	2-2-1-2
3	1-4-1-1	1-1-4-1
4	1-1-3-2	2-3-1-1
5	1-2-3-1	1-3-2-1
6	1-1-1-4	4-1-1-1
7	1-3-1-2	2-1-3-1
8	1-2-1-3	3-1-2-1
9	3-1-1-2	2-1-1-3

Our example code 654321, therefore, would become 1-1-1 4-1-1-1 1-2-3-1 2-3-1-1 1-4-1-1 2-2-1-2 2-2-2-1 1-1-1-1-1-1. The resulting barcode would look roughly like this:

Figure 2.1. MSI exapmle 01234567 mode 10


1.5. Technical Detail		Chapter 3. Printing Considerations