Individual stocks can be the most difficult assets to transfer after death and are often overlooked. If there is no beneficiary designation then the stock may have to go through the probate procedure to transfer, even if you have a will.
Most people own stocks through brokerage accounts. These accounts generally require you to name a beneficiary for the account, making transfer at death relatively easy. However, many people own individual stocks that are in an account with the issuing company's transfer agent. Transfer agents are firms that handle securities transactions on behalf of corporations such as Computershare or EQ Shareowner Services. These agents do not automatically require you to name a beneficiary. For ease of transfer after death, you will need to contact the transfer agent and complete a transfer on death registration - beneficiary designation. (These forms are available on the transfer agent websites).
Be prepared that these forms require a Medallion Signature Guarantee from a qualified financial institution. Not all banks provide a Medallion Signature Guarantee. Often you need a relationship with a financial institution or brokerage to obtain such a guarantee.
Best practice is to open a brokerage account and purchase stocks through these accounts. If not, take the time to complete transfer on death registrations. When in doubt, check with your financial advisor or estate planning attorney.