We have 3 signers-President, Treasurer and Secretary. Usually Treasurer writes the checks and President co-signs them, more for simplicity's sake than anything.
Unfortunately 2 of our signers have children who are ill and when some bills came due it was a challenge getting the 2 signatures so the checks would be "legal"; we were also hobbled over the summer when 2 signers weren't available for extended periods of time and things had to be paid for. In that case one person wrote the checks and when the full board met an explanation was written up and documentation attached regarding each transaction for the audit at the end of the year and it was signed by all 3 signers. We ran everything by an accountant to ensure it was sufficient.
I think the answer is that there is no one-size-fits-all answer, but I'd be leery personally of more than 3 signers unless you have a very large board. (There are ony 5 of us, so half our board is on the account.)

I feel 5 is way to many . Why would you need that many . 3 is all we use our by laws state 2 signatures on a check so we have 3 people on the account . Our 2 co treasurers and the president but the president is only to be used as a last resort .
We decided if worse comes to worse (because for the most part you know in advance when you need a PTO check )a PTO member will use a person check or pay in cash bring in the required paper work and be paid back . No one but the treasure is allowed to have our PTO check book .

Last year our PTO was not run this way and the president with drew a 1000.00 for a field trip to pay for lunch for 70 kids and lost it . No one even voted she could take that money out and she had 2 time what she needed . Checks were signed with no question of how much or what it was for and now the PTO has a black mark against it .

This year the kids have had to do with out a few thing due to this . So I say 3 people on the account and only 4 if this is a case where 1 or 2 people may be hard to contact in an emergency.

You don't want a large group of people actively managing bank transactions, but you need enough to easily keep business flowing. Best practices call for two signatures on a check. Common sense usually dictates that you want a backup signer in case one of the two primary isn't available. It's possible you'd want another backup.

I'd say 3 for sure. You could have 4 or 5, but you also want to control how many people have access to the account. Being a board member doesn't automatically mean being on the bank account. For instance, if someone needed to make a deposit because the treasurer wasn't available, they don't need to be on the account for that.

When I was pres, the primary signers were the Treasurer and President. Back up was our Principal (who was a voting member of the Board and easiest person to track down for a 2nd signature) and sometimes the VP. So we usually had 3, sometimes 4.

But the Treasurer was always the primary manager of the account.

I hoping that someone can help me answer this all puzzling question that is driving me nuts!!! How many of the PTO Board members need to be on the Checking and Savings accounts at the bank? I'm worried we may be getting to many hands on this account. Could they be on it, but not be so called, signers? Please help me if you can. We are about to add at Member at Large which is new to us this year and so that would make 5 signers? Is this too many???
Thanks so much!!!