There are no particular qualifications needed to be an election agent and you can be your own agent if you wish.
However, the following people are not allowed to be election agents:
the (Acting) Returning Officer or a member of their staff1
a partner or clerk of the (Acting) Returning Officer or a member of their staff2
anyone not entitled to vote at the election as a result of the report of an election court or a conviction for a corrupt or illegal practice under the Representation of the People Act 19833
If you are standing as a party candidate, your party may also have specific rules about who you can appoint as an election agent.