It depends on the circumstances & how the yard owner behaves. For instance I was in a situation where I needed out quickly & I moved within the space of about four days. I think it can depend on how you pay too. If you pay weekly only a week, if a month then a month.
If on bad terms, immediately. If on good terms, at least a month beforehand.
I would let your manager know about a month beforehand. Update them two weeks prior.
Depends what time of the month I found a new barn made plans with the owner and left all within a week because we had just had the last lesson of the month
What does your boarding contract say? If you don’t have one, you owe them 30 days notice. You owe a month because you pay by the month.
And if you don’t have a contract, make sure at your next place you DO get one. They cover obligations on both sides so there is no grey area when something happens.
I would say to the barn owner/ manager about a month before about yours plans of moving.
If you’ve signed an Agistment contract it’ll say in there, if not I’d probably do it by when you pay (e.g if you pay fortnightly give them a fortnight’s notice)