I have 6 months on all my gift vouchers. But I am flexible with this. I once had someone come in for a treatment and present me with a voucher she had been given, more than 2 years out of date. I accepted it (though wasn't too happy about doing so), that customer now comes in every 4-6 weeks spending from £50 to £70 at each session. So now I always accept my vouchers no matter how old, but will charge extra if my prices have changed, you never know when a new client with an out of date voucher will become a very good regular client.