Traveling to Spain and want to purchase online tickets for several museums prior to trip. We are in our 70's and qualify for senior pricing in US museums. Are we able to purchase senior discount tickets in the European museums or is that pricing only available for EU citizens?
It varies from country to country. I would probably ask this question on the Spain forum. https://community.ricksteves.com/travel-forum/spain
Our experience is that Spain is the only country that gives a blanket senior discount. Other countries limit it to EU retirees. Just show your passport. Now that was about five years ago so things may change. You ask -- they say yes or no. Simple.
For our week in Barcelona my husband was eligible to get the senior rate for almost all tickets. The Palau Guell was the only that specified either EU (or Spanish?). She simply asked where we were from and then said we were not eligible. None asked for proof and in fact a couple questioned the fact I only wanted 1 for my husband and not for my 60 year old self Grrrr. LOL
The complication comes up in that you may not be able to get tickets well ahead with a discount, but if you are buying in person, they may give it to you. Certainly do not insist, you can ask, if it works out, great, if not, just go with the flow. For what you are spending for the total trip, museum admissions are not going to break you.
If you want to book ahead, just pay the price that comes up.