Philippines
STANDARD: ETSI EN 300 220
Z WAVE FREQUENCY:868.40 MHz, 868.42 MHz, 869.85 MHz
RESIDENTIAL VOLTAGE: 220 V
FREQUENCY:60 Hz
USA
STANDARD:FCC CFR47 Part 15.249
FREQUENCY:908.40 MHz, 916.00 MHz
RESIDENTIAL VOLTAGE:120 V
FREQUENCY:60 Hz
interesting discussion here:
so this means the Philippines uses EU zwave frequency.
which now leads to this possible issue.
with how mostly things are imported from the U.S. and have not heard of any regulation violations as far as I know (i could be wrong though) i doubt it if you will have any issues.
but again as @bobbles said, research first.