It is possible to put life insurance on someone without their knowledge, but there are a few things to keep in mind. First, the insurance company will require some basic information about the person you're insuring, including their name, date of birth, and Social Security number. You'll also need to provide an estimate of their annual income. Additionally, most insurance companies will require you to have a medical exam for the insured person before approving coverage. So, while it is technically possible to get life insurance on someone without their knowledge, it may be difficult to do so without them finding out eventually.