How to invest ‘Subject to’? is a question that puzzles many investors, especially when it comes to beating the “due on sale” clause. The answer to the question “how to invest ‘subject to” is not a complicated one. As long as you are clear with regard to what “subject to” is, it’s not as difficult to execute as it may seem. If you know how to explain it to the seller, and what steps to take to protect you and the seller, you can use the ‘subject to’ strategy over and over with minimal risk to build your real estate portfolio.