I don't understand how this works. If I see correctly, one entity in the chain simply does not pay the VAT it collected. Why is it important that it's cross bor

I don't understand how this works. If I see correctly, one entity in the chain simply does not pay the VAT it collected. Why is it important that it's cross border? I could issue an invoice to my neighbour's company myself and simply not report it. You can always do that and hope you don't get an audit.