Bitcoin Forum

Multisig wallet can go as high as 15 of 15, meaning 15 signatures required for making payment and the other 15 for the total number of cosigners that makeup the wallet. It is like this on electrum wallet on computer but not like this on Android phone, the highest that can be gotten on phone is 5 of 5 multisig. If there are more than 5 cosigners and some of them do not have computer but just phone, it would not be possible to create multisig wallet, only 5 or less than 5 cosigners can use phone.

I have gone through the phone very well, I check settings, I checked if possible I can be able to increase the number of cosigners from 5 to 6 or more, I checked the settings and everywhere but I saw nothing like that. Is it possible for more than 5 people which are cosigners to create a multisig wallet on phone electrum?

The developers chose that because of Android and QR code's limitations (more in the link below).
There was a discussion in Electrum's GitHub repository about that decision: https://github.com/spesmilo/electrum/pull/5133 (https://github.com/spesmilo/electrum/pull/5133#issuecomment-534414139)

I was not aware of this limit at all!
However do we really need that many cosigners for a multi-sig wallet. Possibly few will mess the whole then and ruin the original goal of creating that multi-sig wallet.

There are many things like that which you can do on electrum wallet on computer than phone, 6 of 6 multisig and more keys and signers is not on phone electrum.

There are some few reasons you may want to use more than 5 keys, like a family of 6 or more, it may also be required in business. If a single person wants to use multisig, 2 of 3 is enough.

To be fair these are valid reasons to use multisig wallets not using phone for such setups. For example a business should not use a phone to conduct their money transfers, there has to be some additional setup and security. Not to mention that they may need more complex scripts that Electrum doesn't provide by default.

They never answered to that PR, but my best guess is it has something to do with the standard rule of Bitcoin network, not based from use-case.
Since the maximum number of allowed sigops for P2SH is "15",
the devs might have decided to set 15 maximum cosigners in desktop Electrum's MultiSig wallet setup.

Reference (Bitcoin): github.com/bitcoin/bitcoin/blob/master/src/policy/policy.h (https://github.com/bitcoin/bitcoin/blob/f47dda2c58b5d8d623e0e7ff4e74bc352dfa83d7/src/policy/policy.h#L27-L28)

The more people you get involved, the greater the chances that someone will destroy the entire system. But in theory, that can also happen in a 2-of-2 or 3-of-3 setup if one of the parties is being negligent.

I think pooya87's response to this is spot on. If you need such a high level of security and a system with 15 cosigners, having them sign and approve the transactions via their phone isn't the best idea.