UKBA have some strict rules when it comes to English Language testing.
If you're interested in IELTS (Academic or General Training) I'd strongly suggest following the links on the UKBA list of approved English language tests

Here's the link to their latest List of approved English Language Test

You'll find details for IELTS on pages 17 and 18
There's also links to test centres.....
For Davao these are available:-

British Council - Davao
IDP Education Pty Ltd - Davao

If you need any further clarification just ask