The number to watch
Component stock against set stock. Sanitaryware sells as sets but stocks as components, and shops routinely end up short of one part and long on another — a cistern with no matching seat, or three basins and no pedestals. Keeping components as separate items makes that visible in the stock report rather than at the moment a customer asks. It is the commonest reason a sale is lost in this trade.
Brand, model and finish are the item
Sanitaryware is chosen from a catalogue by an architect or a homeowner who compared three options, and the bill has to say which one was supplied. Brand, model number and finish belong in the item rather than in a note, because that is what a warranty claim, a replacement or a second-phase order will be matched against. It also stops the common error of billing a premium model at the rate of a similar-looking cheaper one.
Sets, and selling the whole bathroom
Much of the trade is a set rather than a piece — a WC with its seat and cistern fittings, a basin with pedestal, tap and waste. Keeping the components as separate items and billing them together gives an accurate stock figure while still producing one clean invoice. It also means you can see which components move faster than the sets they came with, which is where a shop usually finds it is short of one part and long on another.
Site supply for a builder
A builder fitting out twenty flats orders in batches over months and expects to know what went where. Recording each delivery against the site turns that into a lookup rather than a search through the whole account, and it settles the question of which phase a fitting belongs to. Because the amounts are large and the payment is staged, receipts allocated to specific invoices matter more than a running balance.