Technically speaking, anyone of sound mind above the age of 21 (and who is not a bankrupt) can be your executor.
Briefly, an executor is the person responsible for carrying out your wishes as set out in your will in the event you pass on. Their duties typically include making funeral arrangements, applying to Court for a grant of probate to allow them to start distributing your estate, locating your assets, settling any debts which you may owe and distributing your assets per your wishes under the will. Considering the duties of an executor, you would probably prefer to pick someone who you know personally and whom you trust. Crucially, a close relative or friend will often be in the best position to know you and your wishes well, as well as being fond of your beneficiaries.
That said, what happens if after your death your executor decides to reject his or her appointment? Particularly at a time of mourning, being faced with various administrative responsibilities and possibly a court appearance may be seen as burdensome and stressful.
A possible solution could be to alternatively, or in addition to your relative/friend, appoint a professional executor to guide your personally appointed executor through the process and/or to take charge of the more complex administrative duties. This will prove particularly useful in situations where more complex legal matters arise such as where it may be likely that relatives challenge the will (where they are intentionally left out without their knowledge), where assets are located overseas, or where there are trust instruments involved.
Please let us know if you require our assistance.