Every invoice, with the contact and unit resolved

One page of the invoices on file, in primary key order, each carrying the name it was raised against and the unit it belongs to, so a list needs no second lookup. limit caps a page and offset moves the window, so a client reads the lot a page at a time until offset + invoices.length reaches total. collection is measured over every invoice falling due this month, never over the page. structuredRef is the key automatic reconciliation matches a bank line on. Every amount is integer cents.