you need these:

*Original UK issued CNI or Original Notice of Marriage issued by the British Embassy abroad
*Pay the CNI fee
Payable only in Philippine Pesos and in cash at the current Consular rate of Exchange
*Original UK passport
*Original UK birth certificate
*If widowed, present original death certificate of deceased spouse
*If divorced/annulled, present the original divorce decree/annulment papers

refer to this: http://ukinthephilippines.fco.gov.uk...ply-for-a-cni/