How to spot supplier price increases on Shopify

Short version: Suppliers rarely announce every price rise. They show up as a slightly different number on the next invoice. Compare every invoice and price list line with your current Cost per item, calculate the margin before and after, and set a threshold (say 5%) above which you review the selling price.

A supplier raising the price of one product by 8% isn't dramatic. Ten products rising by 5 to 15% over a year, unnoticed because nobody compared invoices with Shopify costs, is how a shop's margin slides without anyone deciding to cut it. Here's a simple routine to catch rises and decide what to do.

Why rises go unnoticed

Nobody compares. Whoever receives the delivery checks quantities, not prices.
Costs aren't updated. Shopify's cost per item stays at whatever was entered last, so reports still show the old margin.
The rise hides in packaging. A case of 24 becomes a case of 20 at the same price: a 20% rise per unit.
Currency moves. A supplier pricing in EUR or USD effectively changes your cost when exchange rates move, even if their price list doesn't change.
Surcharges. New freight, energy or handling lines raise landed cost without touching unit prices.

Step 1: Compare every line with your current cost

For each invoice or price list line, you need three numbers: the new unit cost (after pack conversion), your current Cost per item in Shopify, and your selling price. Export your products (Products › Export) to get cost and price for every variant, then look them up against the invoice in a spreadsheet by SKU or barcode.

Step 2: Calculate the margin impact

Gross margin is (price − cost) ÷ price. Calculate it with the old and the new cost:

Product	Price	Old cost	New cost	Cost change	Margin before	Margin after
Sencha 100 g	12.90	5.75	6.60	+14.8%	55.4%	48.8%
Yirgacheffe 250 g	14.50	6.40	6.95	+8.6%	55.9%	52.1%
Stoneware mug	12.00	4.20	4.35	+3.6%	65.0%	63.8%

Note how a 14.8% cost rise costs 6.6 margin points on a 55% margin product. The lower your margin, the harder a cost rise hits.

Step 3: Set a threshold and review

Not every cent needs action. Pick a threshold for review, for example any cost rise over 5%, or any product whose margin falls below your target. For each one, decide:

Reprice: to keep the same margin, new price = new cost ÷ (1 − target margin). For Sencha at 6.60 and a 55% target, that's 6.60 ÷ 0.45 = 14.67, so round to 14.50 or 14.90.
Absorb: keep the price if the product drives traffic or competitors haven't moved.
Negotiate or switch: ask for the old price on a larger order, or compare suppliers.
Check the pack size: if the rise is suspiciously large, make sure you're not comparing a case price with a unit cost.

Step 4: Update Shopify

Update Cost per item for every changed product, even the ones you decide to absorb. Otherwise your profit reports keep showing the old margin. See bulk updating cost per item.
Update selling prices for the products you reprice, with the bulk editor or product CSV.
If you sell in several markets with fixed local prices, review those too.

Make it a routine

Check prices on every invoice, at the same time as you receive the stock. It's the only time the information is in front of you.
When a supplier sends a new price list, run the whole list through the comparison before the effective date (see importing a price list).
Once a quarter, review profit reports by product to catch anything you missed.

Where Box to Shelf helps

Box to Shelf does the comparison on every invoice and price list automatically. Each matched line shows your current cost, the new unit cost (after pack conversion), the percentage change and the margin before and after at your current selling price. Rises above your threshold (5% by default, adjustable in settings) are flagged in a banner at the top of the review, so you see them before you apply. Applying updates Cost per item, so your profit reports reflect the new costs from that point on.

Questions

How do I calculate the margin impact of a cost increase?

Margin is (price minus cost) divided by price. Work it out with the old and new cost at your current selling price and compare.

Sources

Shopify changes its admin often. Steps were checked against the Shopify Help Center in November 2026; if a menu has moved, the help center links above have the current version.