The Licensing Act 2003 simplified the process of getting what used to be known as an 'occasional licence'. You now simply have to file a 'TEN' (= Temporary Event Notice) with your local authority. (Unless you live in an area covered by a unitary authority, licensing matters are dealt with by the district or borough council, not by the county council).
Simply print out this form
http://www.culture.gov.uk/NR/rdonlyres/5B3ADA1 A-4BC3-4755-85A7-6DCA1129A51B/0/P_TENupdate110 5.pdf
complete it and make 3 copies. Keep one copy and send one copy to your local Chief Constable. Submit the original, plus one copy, together with a fee of
�21 to your local authority's licensing officer. The authority will endorse one copy and return it to you, as an acknowledgement of receipt.
Note that you aren't
asking for a licence. You're simply carrying out your obligation to
notify the licensing authority about the event. (i.e. there's no 'application'' involved and, consequently, you can't be refused).
Chris