When I used to offer it up at checkin, they would always tell me to hang on to it until checkout. If I'm checking out crazy early and don't want to deal with it, I'll go down the evening before and explain my situation and ask them to process it then. They never want the thing at check-in...I assume it has to do with the fact that it's easier in their system to apply the credit or adjustment to a folio that has at least one night already charged to it? I don't know

BBs in the US or PPs in the UK are easily handled at check-out, However when using them when the rate is in a different currency, thats another situation and Id rather give them in when I get there so I will have the time to speak to someone if I feel they werent handled properly or if the conversion rate is too low.

Also a number of times I have Marriott Cheques that I also want to use, and find its best not to mix them together at the same time.

Ive never had a problem with a property not wanting them at check-in, Ive been told to hand them in at check-out. Once I show them where it says at check-in that ends that. Also by giving them in when I get there , I need not worry if they should somehow get lost or if I should forget to give them in at check-out, it has happened.

I have used many PP around the world. The only time I have ever had a problem with the hotel applying it as an "adjustment" was in Rio and Sao Paulo Brazil. I contacted Marriott and they indeed confirmed that the BB's are not to distort the room rate but should be applied as a form of payment credit.

Keep in mind the hotel pays Marriott for the points it issues. So the fewer the points it issues the more money they save.

They do it as an adjustment in Sao Pauli but I really don't complain because they use the real exchange rate. Also the points that post are closer to the folio before the adjustment than after the adjustment was done.

Ren LHR tells you to hand it in at check-out, but they def do the adjustment thing - as evidenced (again) by my final bill at check out. They say that's the way their accounting dept handles it. So I just keep the folio under the door as it shows the correct bill. Cheers.

Point them to the Marriott Exchange rate
 

https://marriott.com/reservation/displayCalculator.mi

I have used it many times. Marriott customer service pointed it out to me and said that if there was any doubt at the hotel they should be using this as their official exchange rate.

Its saved me a ton of aggrevation, plus its hard for the front desk to dispute the rate when its the OFFICIAL Marriott rate.

:D

I noticed that the link has fine print stating:

The hotel can still charge their own rate, although you might have a case if it significantly differs from the rate provided by the online calculator.