Is this illegal or legal if my employer says if our drawer is short that we have to pay out of pocket to make up the difference?
Question Details: The problem is that there is more than one person on the cash registers. At the time of hiring we didn't sign a paper saying that we would pay out of pocket and now they have a paper they want us to sign. It states that if we're short then we will pay the difference. Are they allowed to do this?
Yes, it is legal; an employer may make it a term or condition of employment that employees will make up any shortfalls in their cash drawers, and if you agreed to such--which includes implicitly agreeing by taking or keeping the job, with knowledge of the requirement, as well as explicitly agreeing by signing a document--it is enforceable and legal.
The employer may not, if you do not voluntarily pay any missing funds, take the money out of your paycheck, unless you explicitly and specifically agreed to let them do this. Without an employee's explicit consent, an employer may only withhold from pay those amounts required by law (e.g. FICA: a court-ordered childs-support garnishment). However, the employer could fire you if you refuse to repay the money; and it could also sue you for the money, under the terms of the agreement you signed (though usually, the amount at stake will not be enough to make it worthwhile).
In the case you describe, the employer could not make you repay any amounts prior to when you agree to this requirement, such as by signing the paper--but they could elect to fire anyone who refuses to sign.