No! The problem here is the the Royal Mail had bad records. Discovery doesn't help at all! Discovery just gets you a copy of the bad data. You need good dat

No! The problem here is the the Royal Mail had bad records. Discovery doesn't help at all! Discovery just gets you a copy of the bad data. You need good data, and nobody has it! This is why we invented double-entry bookkeeping 500 years ago. And even if, by fluke, discovery might help because there was actually a good copy somewhere, that means you've already lost by spending a fortune on lawyers in a dispute with a crown corporation! Look at these disputes - lives were ruined over $44k pounds. Suing the Post Office wouldn't be cheaper than that. In a traditional paper based flow, I have my own copies. I talk to a salesperson, get a price, and fax a PO. I keep a copy of that PO on file. The vendor delivers the order along with a waybill. My staff receive the order and count it, reconciling against my order. If the count is short, we check the waybill. Is the waybill short too? Then there was a problem in order flow. If the waybill matches my order, but the shipment is short, then the problem is in fulfillment. I call sales and hash it out. Honest errors happen, and reasonable people resolve them when given the facts. If the salesperson says their copy of the PO looks different, and calls me a liar when I send them my copy, then we have a real dispute. We might have to get a lawyer involved. But this is well beyond honest error. But in most SaaS environments (GB egress, bytes storage, etc), you are dependent on the vendor for the data. There is no practical way to disagree with AWS if they tell you your usage was 20TB and you expected 15. You are trusting the vendor not to lie (maybe reasonable), and also to never make an error (totally unreasonable!). We now have no defense against honest error. B2C is in a similar boat. In olden-times, I knew people who kept a log book and stop watch by the phone and logged all their calls. Every month, they reconciled their phone bill against their log. Just like they reconciled their bank statement against their cheque stubs and deposit slips. But who in this day keeps their own log of PayPal transactions safely outside Paypal? My main safety with PayPay is short latency - they report significant transactions right away so any errors can be corrected quickly.