Theoretically, anyone with rights to a check can take it to a bank and walk out with cash, but it's often more complicated than this. If you want to cash a check, you should ensure first that the check is good; second that either you are the person to whom the check is made out or that the check has received a blank endorsement; and finally that you have appropriate identification to give the bank teller.
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Ensure that the check is good. If you're not the person to whom the check is made out, and have merely had it transferred to you or are cashing it on someone else's behalf, you are one of the people liable if the check fails.
If the check is not specifically made out to you, whoever did receive the check needs to sign the space on the back of it to "endorse" it, allowing it to be transferred to a third party--that is, cashed by you. Without such an endorsement, you won't be able to cash any check that isn't made out specifically to you. If the endorsement is marked "For Deposit Only" you won't be able to cash the check, but only deposit it into a bank account belonging to the person to whom the check is made out.
Though not all banks ask for ID, especially if you are cashing a check with a blank endorsement, it's best to carry some anyway, as ID requests become more frequent along with fraud. Be prepared to provide a current government-issued picture ID--such as driver's license, passport, military ID. If the check can only be cashed by a specific person, you'll need ID to prove that you are that person.
Regardless of how your check is endorsed, if you are not the person to whom it's made out, some banks may refuse to cash it. They may be more amenable to depositing the money in an account--but if you need cash from the check, and are refused by a bank, consider taking it to a check-cashing service. If you do so, remember as always to ensure that the check's good, as you'll remain liable even if you cash it somewhere other than a bank.