Inventory is where boutique profit lives or dies. Carry too much, your cash gets trapped in unsold dresses. Carry too little, you stockout on the bestseller and miss the season. Most boutique owners learn this the hard way — usually in year two when the storage room is overflowing and the bank account isn't.

I'm Carina — boutique owner since 2013, Shopify Partner, and coach to 3,000+ Shopify boutique owners. Below is the honest system I use and recommend: the tools, the spreadsheet, and the 8 numbers worth tracking.

1. When you actually need an inventory app

You don't need a fancy app on day one. Shopify's built-in inventory tracking is enough for the first 6–12 months if you:

  • Carry under ~200 SKUs total
  • Sell only on Shopify (no in-person, no other marketplaces)
  • Have one location (your home or one storage unit)

You graduate to a real inventory app when one of these is true:

  • You're selling in person + online and constantly out of sync
  • You hit 200+ SKUs and tracking by spreadsheet alone breaks down
  • You add a second sales channel (Etsy, Amazon, TikTok Shop, wholesale)
  • You're making purchasing decisions based on gut instead of data

2. The boutique inventory apps actually worth paying for

Stocky (by Shopify)

Free with Shopify POS Pro ($89/mo). Built for retail boutiques: demand forecasting, reorder suggestions, supplier ordering, stocktakes. If you have a physical location or sell at pop-ups, this is the obvious first pick.

Katana

$199+/mo. Stronger for boutiques that produce their own inventory (print-on-demand at scale, made-to-order, mixed wholesale + own production). Overkill for most pure-resale boutiques.

Inventory Planner

$249+/mo. Best-in-class demand forecasting. Worth it once you're at $500K+ in revenue and inventory decisions are costing you real money when wrong.

Sortly

From $29/mo. Lightweight inventory tracking with photos and barcode scanning. Great as a "first real app" before you outgrow it.

Trunk

From $35/mo. Best if you sell across Shopify + Etsy + eBay + Amazon and need real-time sync across channels.

3. The free spreadsheet system that works (for stores under $300K)

Before you spend $200/mo on software, a clean Google Sheet with these columns will tell you 90% of what you need:

  • SKU / Product name
  • Vendor
  • Date received
  • Units received
  • Wholesale cost per unit
  • Retail price
  • Units sold (update weekly from Shopify)
  • Units on hand (auto-calculated)
  • Sell-through % (units sold / units received)
  • Days on hand (days since received / sell rate)

Update once a week. Sort by sell-through %. The top 20% tells you what to reorder; the bottom 20% tells you what to mark down before it goes stale.

4. The 8 inventory metrics that actually matter

  1. Sell-through rate — % of units sold within a target window (30/60/90 days). Above 60% in 60 days = bestseller. Under 25% in 90 days = problem.
  2. Inventory turnover — how many times you sell through your inventory per year. Healthy boutique = 4–6x annually. Under 3x means too much sitting cash.
  3. Days on hand — average days an item sits before selling. Lower = healthier cash flow.
  4. Gross margin % — (retail - landed cost) / retail. Target 60%+ per item.
  5. Stockout rate — % of bestseller SKUs out of stock at any given time. Want this near zero on your top 20.
  6. Dead stock % — units that haven't sold in 120+ days. Should stay under 15% of total inventory value.
  7. Open-to-buy — budget remaining for next season's purchasing. Set this monthly to prevent over-buying.
  8. Sell-by-vendor — sell-through grouped by vendor. Tells you who to keep buying from and who to drop.

5. The 5 inventory rules that have saved boutique owners I coach

  1. Reorder bestsellers before they're 50% sold through, not when they're out. Wholesale lead times will burn you otherwise.
  2. Mark down at 60 days, not 120. A 20% markdown at day 60 sells; a 50% markdown at day 120 still doesn't move.
  3. Set an open-to-buy budget monthly. "I'll buy what I want at market" is how boutiques run out of cash.
  4. Track by vendor, not just by product. One bad vendor can quietly account for half your dead stock.
  5. Do a real physical count quarterly. Your Shopify numbers will drift. Reset them before you make purchasing decisions.

6. What to do with dead stock

Stop waiting for it to magically sell. Options, in order of preference:

  1. Bundle 2–3 dead pieces together at a sharp price ("Mystery Box: 3 dresses for $45")
  2. Run a private "VIP loyalty sale" — email-list only, 50–60% off
  3. Offer as gift-with-purchase over a threshold
  4. Donate to a charity that matches your customer (write off the wholesale cost)
  5. Wholesale-out to a clearance reseller (last resort — you'll get 20-30 cents on the dollar)

The opportunity cost of storing dead stock is bigger than the discount. Move it.

7. Physical storage that doesn't cost you sales

  • Label every shelf or rack by category, then by SKU range
  • Keep top 20 bestsellers in the most accessible spot (you'll pull them daily)
  • Photograph any new arrival the day it arrives — not "when I get to it"
  • Process returns within 48 hours back into inventory (or they get lost)
  • Garment bags for any piece sitting longer than 30 days

Your next step

If you're under 200 SKUs, set up the free spreadsheet above this weekend. Update it every Sunday. That alone will put you ahead of 80% of boutiques your size.

If you're past 200 SKUs and selling on multiple channels, start a free trial of Sortly or Stocky and see if the time saved justifies the cost in your first month.

For the rest of the boutique tools I actually recommend (apps, accounting, fulfillment, the whole stack), the boutique toolkit is exactly that. And if you want me to look at how your inventory's currently set up, the Boutique Store Audit covers it.

Inventory is boring. Track it weekly and it stops eating your cash.

— Carina