Salary change after relocation

Hi, good day!


I would like to ask if it's legal for a company to lower down your basic pay. First, I would like to give you a brief detail. I am originally based in Sta Rosa, Laguna however the company sent me to Cebu to support our newly established branch here.

When I decided to be relocated here in Cebu, they want me to sign a new payment plan, according to the new payment plan, I will get 13k basic salary which is lower than 1k from what I am receiving in Sta Rosa. Although the monthly allowance that they offered to me her in Cebu is more than what I am getting in Sta Rosa. Let me give you a comparison so the picture is clearer for you:

From Sta Rosa                                    To Cebu

Monthly Basic         14K                          13K
Client Premium         2K                           None
Skill Allowance        None                         5K
Location Allowance  None                         2K
Travel Allowance     1K                             1K
Meal Allowance        1K                            1K
Rice Subsidy           1K                            1K 
Gross Total             19K                          23K


I understand that I am getting higher amount in Cebu compared to what I am getting in Sta Rosa, But Im also  considering other things like the computation of my retirement benefit, 13th month pay, etc..



Thank you!