• I guess Euro’s and CHF are accepted in the huts but is either one preferred?

• If we buy a local SIM for an unlocked phone which network should we go for based on coverage? Do we need photocopies of passports etc to buy.

Unsurprisingly, the Swiss gladly accept Euros, just about everywhere in the country in fact. They are Swiss and It's money, right?
I never tried to pay with Swiss Francs in Italy. I'm almost certain they accept it without any problems in Capana Margherita, and I guess they'll accept it the other refuges near the Swiss border, but I can't be totally sure.
Mind you, the refuges in the Monte Rosa area can be busy. That means it's a good idea to make reservations, sometimes well in advance. And when you do that, you can ask about currencies.

I don't know about cell coverage as I rarely use my (Dutch) phone in the mountains.

I always carry my passport when I'm in the Alps, but I don't recall anybody ever asking to see it high up in the mountains. In the valleys it's a bit different, and country dependent. In Italy I usually had to show it when checking in somewhere, in Switzerland less often.

Thanks for the kind reply.

So if anyone can cover the phone topic we are ready to go.

thanks again.

Actually, maybe this has changed recently but euros definitely do NOT go everywhere in the country. I watched one old grandma try to pay in the grocery store, and trust me the reaction was amusing to say the least . Maybe since their recent vote on foreigners....

BUT, with that said, these huts are on the border and I am quite sure they do take both. If it is a swiss hut, they prefer CHF, and may ONLY give you change back in CHF even if you pay in euros, but if it is an italian hut it is probably the reverse. Some also may take visa now which is awesome, you can check their websites. I also highly recommend a reservation. http://www.sac-cas.ch/en/huts.html, I am sure you probably already have it, but there is all the info you will need. For example you can make reservations for the Monte Rosa hut online.

For coverage, from the Swiss side of the border, I can recommend STRONGLY swisscom. They are a bit more expensive, although for a prepaid phone card its like only a few francs, but they have hands down, the best, back mountain coverage. I personally have an Orange company Iphone, but has a small handy to take in the mountains that is Swisscom. The reception may not be perfect, but from the huts there usually is some signal, and actually all the summits we have been on as well. If you are spending more time on the Italian side of things, I couldn't say but the coverage up high should be the same. To simply buy a sim card which is prepaid, I cannot imagine them asking to see a passport. In the huts you also should not need it as well, unless there is some sort of emergency and they need the information there, but I cannot picture that being the case.

Have fun!

Apart from the private huts:

You can pay with Euros in all huts

(source: SAC)