Our by-laws also specify how they may be amended; the change has to be proposed at one meeting and voted on at the next.
In both PTOs I've been involved in, it's just been one signature (mine) -- I think it would be a nuisance to have to get the second signature. We have someone else review the bank statements to prevent fraud.
I am going to be PTO president for the next school year. This past year we have had a new principal and we also had a new PTO president. We have looked at some stuff from the past and see some things that need to be changed in our by laws. How do we go about this? Also I am curious how everyone handles the check signing? Right now the by laws state that there needs to be a signature from a secretary and the PTO treasurer. We always have 2 signatures on the checks but it is usually the treasurer and co-treasurer.