It doesn't really matter if the graft is an inch or so below soil level. In countries with very cold winters, eg northern states of the US the top of the graft is often planted 2 - 3" below soil level. But in the UK (with the exception of certain areas like Scottish Highlands) with milder winters the top of the graft is best planted level with the soil surface.

the worst is you get suckers but they are easily removed so no worries really.

Thank you. Have planted a few bareroots into pots last autumn and will be putting them into permanent position this spring. if the builders are finished.!!

One effect of planting with the graft underground that I have experienced, is that the scion grew its own roots, and lost vigor as a result.