What is NOT necessary for a broker to be entitled to a commission?

For a broker to earn a commission, specific criteria must typically be met. In the context of this question, the focus is on what is not necessary for entitlement to a commission.

A broker can earn a commission without a signed listing agreement. While having a formal agreement is common and provides legal backing in most situations, it is not absolutely necessary for a broker to get paid. Commissions can sometimes be negotiated in other ways, such as oral agreements or even implied agreements based on actions taken by the broker. Therefore, a signed listing agreement is not a strict requirement for entitlement to commission.

The other options highlight conditions that are more typically involved in a broker's entitlement to commissions. A buyer's proposal can be essential in certain contexts, completion of a sales transaction is a key milestone for earning a commission, and Realtor membership can enhance credibility and access to resources, but it isn't strictly necessary to receive a commission on its own.