How can I print business cards with unique codes on them?

Generate bar codes. Save them to your computer. Go to http://us.moo.com/  If you are in another country, they will redirect you to the right url and currency. Order cards. Become fan for life after you get them. Free tip: Get the recycled paper.  Not only will you feel better about yourself, you can write on them as well.  I am always writing on business cards and have a set designed with a blank in the middle just for this purpose. Shameless self serving suggestion: If you use this link to order, http://www.moo.com/share/jf5r2r I get a discount on my next Moo order.  Just, you know, sayin'.  But even if you don't use my link, go there anyway.  It's really, seriously, good.

Have you considered using http://MOO.COM? http://MOO.COM allow you to have different images on every single card.  With short print runs of 50 Business Cards, you'll be able to upload 50 different images, all with unique codes on them.  If you want something different, try the MiniCards (Hlaf the size of Business Cards and much like stick of gum) which come in print runs of 100 and allow you to have 100 different images across them all. Thanks

Variable Data Printing is what you need. It is a feature of Digital Printing. Basically by inserting variable data fields into your artwork, InDesign will import the data within an Excel spreadsheet and populate the variable fields in the artwork. The end result is a large PDF file with each business card containing its own individual piece of data or unique "code" in your case. You can create the PDF file yourself using InDesign and Excel...here is a tutorial on how to do it...http://goo.gl/TQmBQ Or you can contact me 1877.667.7467 or on our website http://www.mmprint.com All we need is your artwork and an Excel sheet and we can do everything including the mailing if you like.

Mail Merge. Think about how you would approach this if you were printing branded mailing labels.  Every label has a unique address as well as a common logo shared on all of them.  But instead of a common logo you want the business card info, and instead of a unique address you want a unique code. Using Mail Merge, you can output a printed document or PDF that has several completed business cards on each page, each with their own custom field. If you don't like Mail Merge, you could certainly set something up in Excel that would achieve the same result. Instead of asking a commercial printer to make business cards with unique codes (which may confuse them), ask them to print the multi-page PDF you created, and then cut it into individual 3.5 x 2 cards; this is exactly the process they go through in printing business cards anyways, but allows you to frame the problem in a way that's easier to understand.