UPC-A (Universal Product Code version A) is the most common and well-known symbology in the United States. You can find it on virtually every consumer goods in your local supermarket, as well as books, magazines, and newspapers. There may be 2-digit or 5-digit Supplement to UPC.

Structure of an UPC-A number
An UPC-A number consists of four areas:
(1) The number System (one digit);
(2)The manufacturer code (five digits);
(3) the product code (five digits);
(4)The check digit (one digit).

UPC-A Properties
Besides the properties to general barcode, the following property belongs to UPC-A:
SupplementarySeparation gets or sets the space between the end of barcode and the begin of supplementary for UPC/EAN in Inches. Default is 0.2 inches.

UPC-A Check Sum
UPC-A check digit is calculated using standard Mod10 method.

ezBarcodeComponent UPC-A Acceptable String Length
ezBarcodeComponent UPC-A can accept 11, 12, 13, 14, 16, 17 digit length.

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UPC-A examples by using ezBarcodeComponent
[C#]



        using ezBarcodeComponent.Winform; 

        //create barcode class
        Barcode barcode1 = new Barcode(); 
                                                                        
        //Specify the CodeData to encode
        barcode1.CodeData = "01234567890123456";
        //Set the Symbology to UpcA
        barcode1.Symbology = Symbologies.UpcA;
   barcode1.SupplementarySeparation = 0.2;

   //Save the image
        barcode1.SaveImageAs("Ean13.gif", System.Drawing.Imaging.ImageFormat.Gif);



[Vb.net]

      'create barcode class
        Dim barcode1 As New Barcode
                                                                
        'Specify the CodeData to encode 
        barcode1.CodeData = "01234567890123456"
        'Set the Symbology to UpcA
 barcode1.Symbology = Symbologies.UpcA
        barcode1.SupplementarySeparation = 0.2

   'Save the image  
        barcode1.SaveImageAs("UpcA.gif", System.Drawing.Imaging.ImageFormat.Gif)
                        

Example of UPC-A barcode images with variable digit length.   
 

Image	Description
	11 digits CodeData = "01234567890" The last digit is the Mod 10 check sum of the first 11 digits. No supplementary part.
	12 digits CodeData = "012345678901" The last digit is the Mod 10 check sum of the first 11 digits. No supplementary part.
	13 digits CodeData = "0123456789012" The 12th digit is the Mod 10 check sum of the first 11 digits. The last two digits are supplementary part.
	14 digits CodeData = "01234567890123" The 12th digit is the Mod 10 check sum of the first 11 digits. The last two digits are supplementary part.
	16 digits CodeData = "0123456789012345" The 12th digit is the Mod 10 check sum of the first 11 digits. The last five digits are supplementary part.
	17 digits CodeData = "01234567890123456" The 12th digit is the Mod 10 check sum of the first 11 digits. The last five digits are supplementary part.

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