Can I apply for British nationality without losing my Dutch nationality?

You automatically lose your Dutch nationality if you voluntarily acquire British nationality as an adult. There are three exceptions:

you were born in the United Kingdom and it was your principal country of residence when you acquired British nationality;
the United Kingdom was your principal country of residence for an uninterrupted period of at least 5 years before you reached the age of 18;
you are acquiring your spouse’s or registered partner’s British nationality.

A minor who acquires British nationality will not lose their Dutch nationality if one of their parents holds Dutch nationality.

More information about losing Dutch nationality