If you're trying to sell a product on Amazon.com, you will be required to have  UPC or EAN code for your product.

What is a UPC or EAN code?

They are barcodes or product identification numbers.

How do I get a bar code

You can learn more about the process by visiting Amazon's 'How to obtain a product code' FAQ.

Is there any way to sell products on Amazon without using a barcode?

Yes, you can apply for a UPC exemption at Amazon.com.