The adhesive on the OL5051CJ labels (clear matte inkjet material) should stick to a plastic employee ID card with out any issue. I am not exactly sure how you intend to use the label on the card so I can't say for sure whether it is going to be a good choice for your specific use. We are happy to send you a sample for testing if you would like to fill out our sample request form: https://www.onlinelabels.com/samples