There are a number of sections in the 1987 Constitution which deal with the issue of succession in the presidency. The first is found under Section 7 of Article VII which states that:

"The President-elect and the Vice-President-elect shall assume office at the beginning of their terms.

If the President-elect fails to qualify, the Vice-President-elect shall act as President until the President-elect shall have qualified.

If a President shall not have been chosen, the Vice-President-elect shall act as President until a President shall have been chosen and qualified.

If at the beginning of the term of the President, the President-elect shall have died or have become permanently disabled, the Vice-President-elect shall become President."

This section contemplates various circumstances when the Vice-President merely acts as President namely when the President-elect fails to qualify or shall not have been chosen. However, in cases of death or permanent disability of the President, the Vice-president is not merely an acting president but shall become President.

Section 8 Article VII also contemplates situations wherein the Vice-President becomes President such as death, permanent disability, removal from office, or resignation of the President.  In the aforementioned cases, the Vice-President shall become the President to serve the unexpired term.

In order to avert a government crisis whenever the President is unable to discharge his functions, the 1987 Constitution states the following under Section 11 of Article VII:

"Whenever the President transmits to the President of the Senate and the Speaker of the House of Representatives his written declaration that he is unable to discharge the powers and duties of his office and until he transmits to them a written declaration to the contrary, such powers and duties shall be discharged by the Vice-President as Acting President.

Whenever a majority of all the Members of the Cabinet transmit to the President of the Senate and to the Speaker of the House of Representatives their written declaration that the President is unable to discharge the powers and duties of his office, the Vice-President shall immediately assume the powers and duties of the office as Acting President.

Thereafter, when the President transmits to the President of the Senate and to the Speaker of the House of Representatives his written declaration that no inability exists, he shall reassume the powers and duties of his office. Meanwhile, should a majority of all the Members of the Cabinet transmit within five days to the President of the Senate and to the Speaker of the House of Representatives their written declaration that the President is unable to discharge the powers and duties of his office, the Congress shall decide the issue. For that purpose, the Congress shall convene, if it is not in session, within forty-eight hours, in accordance with its rules and without need of call.

If the Congress, within ten days after receipt of the last written declaration, or, if not in session, within twelve days after it is required to assemble, determines by a two-thirds vote of both Houses, voting separately, that the President is unable to discharge the powers and duties of his office, the Vice-President shall act as the President; otherwise, the President shall continue exercising the powers and duties of his office."