usually i have my customers write their social sec # on the back of the passport photo, so "if" it does come off or the atf has a fit about it not being attached, they know who's it is... i've had returned form 4's come back because guys didn't attach the photo, i've also had em come back because guys didn't have the form 4's printed front/back (they sent in 4 separate sheets)... so now i do all the 4's for my clients free of charge, so there are no screw ups, IF i were you i would go to the wall mart, and get some clear stick glue and stick it (its what i use), that way when your are "hopefully" approved and your 4 comes back, your photo will be attached well, and you can scan/copy it, shrink it down and laminate it, put it with your weapon, and stash your original in a "safe" place!!!