Hi Brighton2023,
In order to pay National Insurance contributions (NICs) voluntarily for a period outside of the UK, you need to complete a CF83 application form. The form asks which class of National Insurance you are applying to pay.
From what you have said, it sounds as if you applied to pay Class 3 NICs? However, without being able to check your record we are unable to give a definitive reply. Please contact our National Insurance team for advice as they will be able to view your original application.
National Insurance: general enquiries
Thank you.