Immigration clearance for domestic travel

You will need to have your passport available for inspection (which will have the 30 day visa stamp from when you entered Manila) for domestic travel. There is no additional immigration clearance required.

Bob is right, no imiratin clearances for domestic flights, but the rule here is no matter where you go, take your passport with you,

samangelevski wrote:

Bob is right, no imiratin clearances for domestic flights, but the rule here is no matter where you go, take your passport with you,

That's a good idea in many places but there's always the danger of losing an important document.
Perhaps I could offer the suggestion of using a hidden wallet, basically a pocket that slips inside your trousers.
When travelling, I pop my passport into a thin plastic bag, then pop the thing into a wallet of the type I've illustrated below. Safe, but easy to get to if needed.

When I'm home my passport is kept in a safe place as there's little need here to carry it on my person and can access it easily if needed.
When I travel to Cebu I take it with me and upon arriving at my other house it is stored in another safe place so if I need to I can access it within the hour.
Only time I have needed to produce it is when paying the annual permanent residency fee in January each year.
I believe it is safer to do it this way in case of robbery when just doing domestic stuff. Filipinos know in their hearts that foreigners fart money and valuables and some look at us as prey.
Passport loss is a very major problem so best not to take chances.

Hi Leva,
Back to your question.
Bob and Sam have it right.
Immigration and customs check at point of arrival as an international passenger. After that you are a domestic traveler and no more immigration checks.
Have fun and enjoy your stay.