My earlier post still stands.. Take Samsung for example... I can get a Samsung tech guy to come over to my place to fix an issue with a TV, HT or Soundbar. They go by serial numbers and registered date. So as long as their system shows an active subscription, I guess they don't care so much about the receipt. Same thing with Acer laptops, even with extended warranties. The same may not be possible if one's trying to claim warranty on a Samsung phone at the service center. Most likely, you'll be asked for the receipt as proof of purchase.