I am flying the return leg of a BKK-AMS-CDG flight. On the way over, I was able to use miles to upgrade at the airport (I am Delta Platinum) even though I think normally that might not be allowed. The Thai KLM check in manager was pleased that I could speak some Thai, so I think I was lucky, but also 40k miles lighter.

So, I didn't have to worry about my luggage weight that time...but on the return flight, I will be in economy again and I'm wondering what my allowance will be? 20kg, 30kg, or maybe just "2 pieces"? The flight was booked on NWA.com, has KLM numbers and will be KLM metal, but it seems that I manage it from Delta.com now in the itineraries section. Delta said 2 pieces, but I don't know, I'm not sure that it right. I just don't want to show up with 30kg and get hit with a hefty charge.

Thanks!

ps. kind of a separate question, but last time I checked in online, i was sent to KLM and I was offered the chance to buy a biz class seat upgrade for something like 240 euros, is this common? I kind of hope it happens again!

Cheers, Powers