The executor or, in many states, personal representative sees that your will is carried out. It is tiresome, detailed, time-consuming, thankless job. You are doing no favors for the person you name. All the property has to be tracked down and assembled (no easy job if you did not keep good records). Creditors notified. Heirs dealt with tactfully. Arguments settled. Bills and taxes paid. Property appraised and distributed or sold. Life insurance claimed if it is payable to the estate. Investments managed until they can be distributed to their new owners. Final accounting to be made, to the heirs and, perhaps, to the courts.
The executor usually works with a lawyer, so you do not need an expert in estate law or high finance. You need virtues that are much harder to find. An executor has to be willing, reliable, well organized, honest, responsible about money, fair-minded, and sensitive to the worries of the heirs. The usual practice is to ask able heirs (or friend) to do the job. If you name a professional executor a bank or a lawyer include a family member as co-executor, just to keep things moving along. Get permission before putting down someone’s name. If money is misspent or errors made, the executor can be held personally responsible.
A friend or family member usually doesn’t ask for compensation. But you should specify this in the will; otherwise, they may claim the commission allowed by law, even though you expected them to serve for nothing. (In large estates, it may be cheaper for a family member to take a commission than to take the same amount of money as an inheritance. The income tax on the commission may be lower than the death tax on the net estate.)
When banks or attorneys are executors, however, they may charge, and charge, and charge sometimes by the hour, sometimes a fixed fee, sometimes a percentage of the assets in the estate that goes to probate. Your estate will pay less if you keep the executorship at home and let your family hire a lawyer by the hour or by the job. (Executors should shop lawyers, asking more than one what they will charge; like any other business people, lawyers cut fees for jobs they want and that they know are up for bid. Your family may not even need an attorney.