A former mayor of Ipswich has successfully appealed against a Home Office decision to deny her British citizenship.
Inga Lockington, a Danish national who has lived in the UK since marrying her husband Tim in 1979, said she was pleased the issue was being resolved.
She decided to apply for UK citizenship after the Brexit vote in 2016 but was initially refused as a permanent residence card did not accompany her application.
But on review the Home Office found her settled status since 1979 had not been correctly evaluated.
A Home Office spokesman said: "We have contacted Mrs Lockington to advise her that, following reconsideration of her case, her citizenship application will be granted.
"We have also taken the opportunity to apologise to her for the initial decision."
It said guidance has been reissued to reinforce the importance of consideration of wider immigration status in all cases for citizenship.