Many people ask me the following question, or variants thereof:
Can I use your site to make a barcode for my product?
There are different answers to that question, depending on what you mean. Here are some possible questions you might have meant.
The answer to this question is a most vehement "yes." That is, if you have a number in mind, you can enter that number into the form and submit it, and the image that you get will be a proper image of the barcode representing that number.
For example, as I write this, I am looking at the box that holds my Mr. Twister MooMixer, an excellent device that everyone should own. On the bottom of the box is a barcode bearing the number "605168104036". If I enter that number into the form on the main Barcode Server page, and look at the resulting image, it looks identical to the barcode that's printed on the box. If I print out this code and hold it in front of a cash register scanner at a place that sells the Mr. Twister MooMixer, then I will almost certainly be rung up for a Mr. Twister MooMixer.
In fact, one of the original things I did to test the Barcode Server was to reprint a barcode for a music store's "listening station card." It worked like a charm.
Some people seem to have trouble with the image format that the Barcode Server uses. This page may be of help to you if you are such a person.
The answer to this question is pretty much "no." There's a big organization called the Uniform Code Council which is the official organization that assigns barcode numbers for businesses and products. If you want to put a barcode on a product and expect that barcode to be functional and not conflict with the barcodes from all the other products in the universe, then you need to go through these guys (and pay them money) to get an official product number assigned for your company and/or product.
Having never had to get an official number assigned for myself, I don't really know what all's involved in this process.
Of course, if you're interested in "sticking it to The Man," then one way you can do this is to make up barcodes to put on the stuff you sell and not worry whether it conflicts. Or, even better, you can pick a number of some particularly salient product in order to guarantee a conflict. Maybe you want your compact disc to be counted as a box of adult disposable undergarments, or something. The "Cement Cuddlers" story features such a humorous (mis)use of barcodes.
No, I don't mind at all, if you're just using the server to look at one or two barcodes, on an occasional basis. However, you may not abuse the server, where abuse is, say, regularly using the server to view more than a couple barcodes a month.
Right now, you're pretty much on the honor system. I have a minimal bit of security that prevents the most egregious abuses of the system. If you get into abuse territory, I'll eventually notice, though, and you may cause me to run out of my CPU quota from my ISP. In the mean time (before I up the security ante again to thwart your evil plans), you'll be losing karma points and will have to live with your own guilty conscience. Granted it's not as bad a sin as killing an innocent human; I'd count abuse of the system as a transgression of the "show kindness to your neighbors" dictum or "don't wear out your welcome," or however your religion (or other moral standard) puts it.