The number of people needed to sign your will for it to be legal varies depending on where you live and the details of your will, but most states require that you, as the testator, and two witnesses must sign it. As of December 2010, only Vermont requires three witnesses' signatures in addition to the testator's. Check with an attorney in your area to learn what a will in your state requires.
Witnesses
Your witnesses must watch you sign your will so they can testify later, if need be, that you were of sound mind and not doing it under duress. State to your witnesses that what you are signing is your will, though it is not necessary for them to read it or know what it contains. If you sign your will at an attorney’s office, most states will not allow her to be a witness.
Beneficiaries
Laws vary from state to state as to whether or not beneficiaries in your will -- the people you are leaving inheritances to -- can be witnesses. Many states provide an option when this occurs, and you would either need one additional witness in addition to the beneficiary, or the beneficiary can waive his inheritance. If he is a relative, he might then be able to receive a portion of your estate equal to whatever he would have gotten if you had died intestate, or without a will. Some states forbid beneficiaries from being witnesses at all. There is usually nothing prohibiting your executor from witnessing and signing your will, but check with your state to be sure.
Notary Public
It is generally not required that you have your will notarized. However, there is an advantage to doing so. When a will is notarized, it is “self-proved” and most states will automatically accept it as authentic for probate purposes, which means that your witnesses will not have to testify after your death that they were there when you signed it and that they signed it as well. If you have your will notarized, the notary will sign it in addition to you and your witnesses.
Holographic Wills
Most states define a holographic will as handwritten and unwitnessed, so no one other than you has to sign it. But not all states accept holographic wills under those terms. Some states accept handwritten wills if they were witnessed. Holographic wills generally have to be written entirely in your handwriting, as well as signed and dated by you.
Read More: States Where Holographic Wills Are Legal
Extraordinary Circumstances
You may be unable to sign your own will under some circumstances. Most states allow someone else to sign your name for you in these cases. In general, this cannot be one of your witnesses, so this, too, would require an additional signature. The person signing for you must usually also sign his own name and indicate on your will that he signed it for you at your direction.