Cook Islands → United Kingdom
Cook Islands plugs
Type IUnited Kingdom plugs
Type GNo shared plug types. A travel adapter is required.
Compatibility: Adapter Required
Voltage — Cook Islands 240V — United Kingdom 230V
Voltage difference is small. Most electronics will work safely.
Device compatibility (phones)
Phones almost always support 100–240V, so yours should work safely. Check your charger label to confirm.
You likely only need a plug adapter (if socket shapes differ). Voltage is close between these countries.