I am doing this, I had 225 35 19 Pirelli allround, I purchased 2x new 235 Goodyear which I fitted to the rear.
The Pirelli originally fitted to the rear still had 7mm of tread so I have put them on the front to hopefully get a little use out of them?
(Like getting your moneys worth?...Etc....
)
This tyre combo was fitted the day before a service and Mot at a reputable VW main delaer, the car passed the Mot with no comment made on the tyres.
As stated above fine as long as the tyre size match on the same axle.