Water meter inlet size 20mm or 25mm

Hi,

I am owner building and need to move our water meter. It is currently right in the middle of our stairs to our front door and is a 20mm inlet.

I believe in Victoria if I move it more than 600mm I need to get the water supplier involved to do it. Our plumber has suggested since we have to move the meter more than 600mm and need a new inlet line, we should upgrade to a 25mm water meter and inlet at the same time.

Is this advisable for a 5 bathroom + powder room house? He seems to think so. Yarra Valley Water has quoted $1400 as for the 25mm upgrade to the line. Then there is the $3000 for the plugging and tapping the main water line and another $600 they say as the mains is on the other side of the street. So this is $5000 all up. Not a cheap exercise.

Any advise would be appreciated. Does the water supplier do all the work for this? If anyone has been through this and can explain the process. Thanks.