If “you” in the question is a new agent for the buyer and had nothing to do with the property previously, no problem.

If, however, the agent is agent for the seller, knows that the buyer intends to flip the property and knows, or has a very good idea, that he can get the buyer a better deal than what he obtained for the seller, then the agent has a large ethical issue.

But if agent for the seller has obtained for the seller the best deal he could, and sometime after the deal is signed the buyer then decides to put his equitable interest on the market or another buyer approaches the agent, there should be no problem. After all, the seller’s agent had not been able to obtain a higher price for the seller after marketing it for some time, the seller was satisfied with the deal, and now just because the buyer thinks he can resell for more, why shouldn’t he be able to give it a try? Of course, the seller may not believe that the agent and the buyer didn’t have this set up ahead of time–(the temptation of a double commission for the agent)– and in this case probaby won’t give his permission.

We “know” it happens often where the buyer and agent know of a better buyer for the equitable interest even before the original sales agreement is signed. This is unethical, if not illegal(but how can intentions be proven?).

Today, however, if the transfer tax applies to a flip situation, the better procedure would be for the buyer to close, then try to resell. Two transfer taxes are going to have to be paid anyway and this would preclude the possibility of any lawsuits.