More than 2 people applying for a mortgage

Highly unlikely for a main home mortgage.

Some would look at it for investment mortgage - but you need 30% deposit and you pay higher rates.

And it this "must get on the property ladder" that causes huge issues in future if prices drop.

Patience and 2-3 years of hard saving is the only real option.

Seen a few cases of siblings buying together and then one finds a partner and can't buy the other out leading to them falling out.... Can't see such an arrangement with ftiends working unless they bought a property to subdivide it.

Yeah banks could do this if they wanted, why couldn't they? That's the answer to the question you asked.

But like every mortgage application, it will be taken on its own merits and will likely be a no.

Way too messy for banks they'll foresee problems down the line, just like posters here have, and you have, since you expected these concerns in your OP.

Why does your daughter need 3 friends to go in with her? Could she not try it with just 1 friend? Incomes must be low or trying to buy in a very expensive area if they need 4.

How will 4 people ever be on the same stage of life for long enough for this to make sense or build any equity?

Will there be buyouts in the future? What's the exit strategy. If one wants out will the banks transfer property to the remaining 3? Where will the money come from to buy out equity if someone leaves? Would the house be put up for sale in this case? Where do they all go from there?

These are the questions that the bank will need to be satisfied are answered, and I don't think there are any satisfactory answers they could give.

I think it would be reckless of the bank to say yes to it to be honest

Objectively terrible idea. There is zero chance that it won't end badly.

Banks will consider lending, but 3+ borrowers is a massive red flag. It's basically a bunch of people who cannot afford it

(1) if things go bad (interest rates go up, etc) none of them as individuals will have a sufficiently large interest in resolving the situation.

(2) the situation is designed to degrade; i.e. eventually people will want to leave, from other households, sell up.

It's not about policy, it's about risk.

I appreciate your question was to do with could rather than should but for daughter and friends experiences might prove useful for others thinking about doing something similar.

Out of curiosity did your daughter and friends discuss how they would amicably go their separate ways? What kind of agreement or plan is in place? Is it formal/informal?

Is the property they're interested in easily convertible to 2/3 separate units?

I really hope it works out for them. I'm in my late 40s and knew a LOT of my friends/associates/ workmates that did this back between 2000-2007. Something always went wrong, unfortunately. But I wish them the best.