I am travelling in and out of Canada, around once a quarter. Therefore the prepaid plan is the best cost effective plan for me. I can pay only for the call minutes that I need when I am in Canada, and at the same time I can keep the same phone no. under the basic plan. I have bought a top-up voucher of $15 when I left Canada recently, so that I can still top up my account to keep my basic plan when I am overseas. It is because I am told that international credit will not be accepted for payment. My question is what is the validity of the top-up voucher PIN ? I asked at the Kooko kiosk when I bought it, the staff was not sure. One said seems to be 60days, and one said perhaps 90days. Will you please clarify for me?