Afraid to Assess Property for fear of raised Taxes?

[Mark M.]

I have had numerous people tell me its better not to have the town / city know about changes to a property so your taxes dont go up.  They shy away from having the town assess a property as well as town knowing about upgrades inside / outside to the house.

They state if the town / city knows, then taxes will go up and more comes out of your pocket.  But is it actually better to have the town / city know accurately what a property is worth?

Thanks