When you buy inventory, that purchase doesn’t immediately show up as an expense on your profit and loss statement. It sits on your balance sheet as an asset. Only when you sell that inventory does the cost move from the balance sheet to your P&L as Cost of Goods Sold. Your gross profit is revenue minus COGS, so whatever number lands in COGS directly changes your bottom line.

This is where many small business owners run into trouble. Say you buy $15,000 in product this month but only sell $9,000 worth. Your COGS should reflect $9,000. If you’re expensing everything at the time of purchase instead, your P&L shows $15,000 in costs and your profit looks $6,000 lower than it actually is. The reverse happens too. If you sell through old inventory without buying much new stock, your P&L might show unusually high profit because COGS appears low relative to revenue. Neither picture is accurate.

The valuation method you choose also changes the numbers. FIFO (first in, first out) assumes you sell your oldest inventory first. When supplier costs are rising, FIFO results in lower COGS and higher reported profit because the cheaper, older items are what’s hitting your P&L. Weighted average cost smooths things out by blending all your purchase prices together. Each method is valid, but they produce different profit figures from the exact same transactions. Once you pick a method, stick with it for consistency and to avoid issues at tax time.

If you’re not doing regular inventory counts and matching them to what’s in your books, your P&L is essentially a guess. Shrinkage, damaged goods, and miscounts all create gaps between what your system says you have and what’s actually on the shelves. Those gaps quietly distort your profit margins until you reconcile. A quarterly count at minimum keeps things honest. Monthly is better if you carry a lot of SKUs.

Proper inventory accounting means your P&L reflects what’s actually happening in your business, not just what’s flowing through your bank account. That clarity is what lets you make real pricing decisions, reorder at the right time, and understand which products are truly profitable versus which ones just move volume.

If your financial statements have never felt like they match the reality of how your business is performing, inventory valuation is one of the first places to look. A bookkeeper in Long Beach who understands product-based businesses can help you set up the right method, keep your counts aligned with your books, and give you a P&L you can actually trust.