I get plenty of those, too. It is almost always a robocall, but sometime it is a potential new client that I wouldn't want to miss. So, instead of answering, "Hello", or "Yes", which the robot recognizes, I say, "Good morning. How can I help you". If it is a live person needing tax services, they will ask an appropriate question. If it is a robot, it will wait for 3 seconds and disconnect. Then I block that number. Of course that doesn't always work as the robocallers will switch to another number, but at least it stops the less sophisticated ones, like those asking for a donation or to answer a survey.