n airplane on an IFR plan can conduct a visual approach. Do you really think we’re talking about cancelling IFR?
I think that is what happens here in the U.K.
Standard phraseology here might be aircraft requests visual approach. Aircraft cleared visual approach and requests cancellation of IFR flight plan. Controller confirms IFR flight plan cancelled at [time}.
The U.S. is very different to most places in the world as I keep saying.