There does seem to be some disagreement over whether Lintmill in in Banff or Moray!
It is actually in both, depending on your definitions of Moray and Banff.
Lintmill is unequivocally and without question in the County of Banff, also called Banffshire*. It straddles the boundary between the parish of Cullen and the parish of Deskford, which runs along the Burn of Deskford at Lintmill. Both parishes are wholly within the boundaries of the County of Banff.
However the County of Banff as a local government area was done away with in the reorganisation of local government in 1975, and the parishes of Cullen and Deskford both became part of the new district of Moray, which includes about two-thirds of the County of Banff. So Lintmill is (also) unequivocally and without question in Moray. It is not, of course, and never has been, in the historic County of Moray.
The remainder of the County of Banff, including Fordyce, the next parish to the east from Lintmill, became part of the new district of Banff and Buchan; this was done away with in its turn in 1994/5 and became part of the expanded Aberdeenshire.
Although it no longer exists
as a local government area, the County of Banff still exists; the present local authorities have erected road signs where the main roads enter the historic county, and it remains as it was for ceremonial purposes; there is still a Lord Lieutenant of Banffshire, for instance.
*but never 'Banff County' or 'County Banff'. That style of designation is never used in Scotland.