NNN Lease Reconciliation methods

[William Masters]

Hi!  For Triple Net Leases, how are the net charges generally handled/administered?  Does the landlord send an invoice monthly/quarterly/yearly for the actual tax/insurance/maint costs to the tenant to pay up, or does it normally work differently?  Are the charges estimated monthly, and reconciled for actual at year end?  Thanks so much for any help.  This is my first post here, and I am hoping to learn what to expect when leasing.  Thanks!