Shopee vouchers should not expire.

Shopee expires because as per Shopee legal:    

"Upon further evaluation, if the purpose of the e-vouchers is to entitle Shopee users to a discount or exchange of pre-identified goods, they are deemed excluded from the coverage of the Gift Check Act. Under the law, "coupon" or "voucher" refers to any instrument issued to any person, natural or juridical, for monetary consideration or otherwise, that entitles the holder to a discount off a particular good or service, or that may be exchanged for a pre-identified good or service specified on the instrument.... Given the set of circumstances in your email below and provided that the e-vouchers are compliant with the foregoing, we would like to clarify that the e-vouchers may have an expiry date and should be deemed excluded from the coverage of the Gift Check Act."