Birth Certificate-2nd Name Problem

Hello. Good day to you sir/madam,
Thank you in advance already. The situation po is my father's name in NSO is Mark Javier (2names) born 1954 unfortunately po all his documents ang name po is Mark Philip (different second name) from school docs to government Ids etc. my father is retiring soon and ang worry po namin is magkaron ng problem pag retire nya. Benefits will not be release or honored. Any ideas po on what to do to change his name in NSO and to prove na same person lang po. Without spending too much po. More power. God bless.

Two approaches, you can file a petition to change Javier in the NSO certified birth certificate through the Office of Civil Registry but this will go through a court proceeding requiring submission of documents. You can consult the OCR help desk regarding this.
Another approach is the use the current NSO certified BC and have all the other identification of relevant or all institutions e.g. government, school, SSS, GSIS, baptisimal, BIR, Philhealth, postal, bank, PAGIBIG updated to Mark Javier from Mark Philip on the strength of the BC. This requires submission though of other supporting documents depending on the institution. You may start to ask around some institutions how this is done. If only one name is used in some, I believe it does not need updating.