Real Estate properties for sell show are vulnerable to misuse, especially if key is placed in a mechanical lock box. System and method is proposed to validate the caller as being a real estate sales associate. The proposed system is always updated with active agent' s roster identities. Some scenarios of updates are : when real-estate commission issues a license, when a licensee joins a broker office, and when a licensee changes sub-broker office, when he becomes a referral source or if his license is suspended, revoked. Methods are discussed in which access is made available to an agent sitting in the broker allocated call centers. When a caller calls, to the broker (sub-broker) call center for inquiring about sell show, the proposed system from the calling number identification data makes a search in the agent roster repository. Actions are taken based on yah nay. If yah, combination lock info is provided, if nay, call is either declined for the combination info or more information is taken to validate the caller. An incoming call to a sub broker office can now be traced, verified and logged. We present centralized and distributed processing schemes for article of manufacture.