Every growing company has contracts that were signed but never billed, and invoices that do not match what was sold. Finding them is tedious; not finding them is expensive.
Match on three keys
Match contracts to invoices by account, product and period. Anything that matches on two keys but not the third is usually a pricing or timing problem worth a look.
Sort the gaps by size
Most mismatches are small and harmless. Sort by dollar variance and start at the top; the first ten rows usually hold most of the money.
Fix the process, not just the row
When a gap repeats, trace it back to the handoff that caused it, usually between the signed order form and the billing system.
