Small business owners: what do you still track on paper?

We're the team at AiRedHQ building vkRetA for Indian shops: boutiques, salons, home bakers and kirana stores.

When we talk to owners, the same notebooks keep coming up: the udhaar (credit) book, the stock register, the order diary for WhatsApp orders, and the appointment diary at the salon desk.

If you run or help a small business: what is the one thing you still track on paper, and what stops you moving it to your phone? We'd love to hear the honest reasons, even if the answer is "paper just works".