Yes depending on your application, application professional, if they had been taken care of, and they are removed properly.
Can I re-use my hair extensions?
Yes depending on your application, application professional, if they had been taken care of, and they are removed properly.
kerridawn.info 
you can reuse them as long as you take care of them. my clintele usually buys a new set after 6-7 months becasue they do get ratty. If you remove them soak them in fabric softner for 10 minutes then rinse thouroughly. They will be softer and easier to handle.