You Do Need power plug adapter while traveling from Pitcairn Islands to United Kingdom (UK).

Here is Why You Need An Adapter

The outlet and plug type used in United Kingdom (UK) is G and in Pitcairn Islands is I. This is how they look like.

In Pitcairn Islands, outlets of type I are in use.

Type I

In United Kingdom (UK), outlets of type G are in use.

Type G

I am from

going to