How Do I Keep Track of Inventory When I’m Busy Running the Business

I run a small e-commerce business, direct to consumers, fulfilling orders ourselves. And for the first couple of years, my inventory system was memory, instinct, and mild panic. I'd sell through a best-seller without noticing until customers started emailing asking where their order was. I'd over-order slow-moving SKUs because I forgot I already had stock sitting in the warehouse. It is a classic SMB chaos.

I'm not going to sell you on fancy software. What actually fixed it was something far less exciting: a boring, consistent routine for how to keep track of inventory I could stick to without hiring a dedicated inventory manager. Here's exactly what that looks like.

1. The first problem was having multiple "truths."

Before I fixed anything else, I had to fix this. I had what I thought was in stock, what my Shopify dashboard said, what my supplier invoices showed, and what was physically sitting in our fulfillment area, and none of them agreed. That's not an inventory problem. That's a data problem.

The easiest way to keep track of inventory, I learned, is to pick one place where everything lives and commit to it completely. For us that became Shopify. Every sale reduces stock automatically. Every incoming shipment gets entered the same day it arrives, not when I get around to it, that day. If something gets damaged or goes missing, I log it. That last part matters more than people think. Unlogged losses are where phantom stock comes from, and phantom stock is why you think you have 40 units when you actually have 22.

One source of truth. Everything else follows from that.

Second problem: I was tracking too many fields.

I built elaborate spreadsheets with thirty columns and updated them for two weeks before abandoning them entirely. The only fields I actually needed to keep running inventory accurately were five:

• Item name and SKU
• On-hand quantity
• Supplier
• Lead time in days
• Reorder point

That's it. If those five stayed current, I stopped running out of things unexpectedly and stopped over-ordering things I didn't need.

If you're figuring out how to track inventory for small businesses, resist building the perfect system on day one. Build the minimal system and actually use it.

The reorder point is what made inventory feel automatic.

This one concept changed how I think about running inventory day to day. Instead of asking myself "do I need to reorder this?" which requires me to remember, check, and decide, I set a trigger number for each SKU.

The formula for how to keep track of inventory: reorder point equals safety stock plus average daily units sold multiplied by supplier lead time. If you don't know your daily use precisely, divide last month's sales by 30. It doesn't need to be perfect, it needs to be close enough that you're not making decisions from memory.

Once reorder points were set, ways to keep track of inventory stopped being about constant monitoring and started being about responding to alerts. The system flags, I act.

I stopped counting everything and started counting the right things.

Full counts across every SKU are unsustainable when you're running the business yourself. What works is tiered counting: top sellers and high-value items counted weekly, medium-volume SKUs monthly, slow movers quarterly. This is the only approach I've found that keeps how to keep track of stock inventory realistic without it eating your week.

The 30-minute weekly ritual that eliminated most of my stockouts.

Same day, same time, every week. Pull the low stock report. Spot check top sellers. Draft purchase orders. Confirm lead times with suppliers. Send everything in one batch.

Thirty minutes. It sounds almost insultingly simple. It worked better than anything else I tried.

Office supplies are everyone's blind spot, including mine.

Packing tape, labels, bubble wrap, printer ink. Nobody thinks of these as inventory until you're mid-fulfillment day and someone's doing an emergency run to Staples. How to keep track of office supply inventory doesn't need its own software. One spreadsheet tab, a minimum quantity per item, and a visual rule: if you open the last roll or the last box, you reorder that day. Assign one person to own it. Check it monthly. Done.

If you're overwhelmed and looking for the easiest way to keep track of inventory as an e-commerce SMB, don't start with software. Start with one source of truth, five fields per SKU, reorder points on your top sellers, and a weekly thirty-minute block you actually protect. And if you do not have time to invest, you can hire a pre-vetted VA who knows how to keep track of inventory.