Hi Brighton2023,
In order to pay NICs voluntarily for a period outside of the UK, you need to complete a CF83 application form.
This 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?
Without being able to check your record we are unable to give a definitive reply.
Can we suggest you contact the NI helpline on 0300 200 3500.
Lines are open 8am – 6pm Monday to Friday.
National Insurance: general enquiries
They will be able to view your original application.
Thank you.