Mzamo

If you are running 3 phase equipment then a problem can occur, but most don't run that sort of equipment and really only need a single phase.
Most Grid suppliers will tell a installer which phase they would prefer the inverter to be installed on so they can balance the phases. With 3 phase and some equipment a difference of a small number of volts between the phases can cause havoc hence the reason why they choose where it goes. Some companies are allowed to test the phases and then add to the lowest phase but this will depend on your area.
Most simply convert there whole house to run on a single phase (the same phase as given above) as it's a lot easier and never have to worry about balance issues and makes things simpler for all parties envoled.

Hi @Mzamo
I have a three phase supply from City Power but only use one of the phases for my house and have a single phase inverter.
It is not an issue.  
Prior to getting my inverter my house was running on all three phases but it was very easy for my installer to convert to a single phase supply.