Originally Posted by L_D_M

They are expiring, yes. And I'd rather use three vouchers for an upgrade like this rather than use them for three domestic legs. I don't have five vouchers to hand, so that's out of the question.

Do you know if the Jet Airways site specifies five for J to F? From what I can see, a single voucher gives you a one-cabin upgrade for 1500 miles of flown distance, by which reckoning it ought to be three for BOM-CDG.