Citizens of nearly every country can get a visa upon arrival in the Philippines. This will allow you to stay for up to 30 days (Visitors from Israel and Brazil get 59 days). Prerequisites are a passport valid for at least six more months and a return ticket.
You can have this visa extended to 59 days at one of the offices of the Bureau of Immigrations for about 3,000Php.
If you plan to stay longer, you will be required to get an ACR or ‘Alien Certificate of Registration’, which is fairly easy to get; it just requires time and paying up some more.
Overstaying your visa is not recommended, as you will be fined. Plan ahead to avoid being at the mercy of potentially arbitrary and corrupt officials. If you do overstay, fix the issue before heading to the airport to leave the country. Once at immigrations, you will have no other option but to pay up whatever amount you are told to, knowing your flight will leave in a couple of hours.
