If you're buying from a regular supplier — for stock, materials, services — the new Vendors module gives them the same dignity Customers got. Add a vendor at /business/vendors, log their contact + opening balance, then assign them to expenses, fixed-asset purchases, and stock receipts as you record them.

The per-vendor statement page shows everything you owe, everything you've paid, and the running balance. Most useful for credit purchases — you can see at a glance how much you owe each supplier without scrolling through your expenses list.