Subtitle - not all Y fares are upgradeable.UPGRADE AWARDS
Economy Class tickets purchased on Singapore Airlines must be booked in S, Y, B or E booking classes to be eligible for the upgrade redemption award.
Alby If you only get a credit of 10k points for having a paid upgradeable Y ticket then your cash is being trashed by not going directly to points if you have them.
That is the difference in 45k less 35k in your example.
Get your supplier to send you the ticket money they would pay and you can book it your way!
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