For how long are my vouchers valid? Corbin Flak March 22, 2017 13:26 Updated Follow All vouchers are valid for 12 months from the date that they are sent to you. Related articles How do I redeem an ONS course voucher? I didn't pass my ONS online course. Can I retest? What is the cancellation/transfer policy for courses purchased with a voucher? What is the bulk pricing for the ONS/ONCC Chemotherapy Biotherapy Certificate Course? How and when are vouchers sent? Comments 0 comments Article is closed for comments.