The formula
A floor is the price at which, after fees, the returns allowance and your minimum margin, you still cover landed cost. With a payment fee of f percent, a fixed fee, a returns allowance of r percent and a minimum margin of m percent of the price, the floor is (landed cost + fixed fee) divided by (1 - f - r - m), with f, r and m as fractions.
Round up to the next penny. This is an authored method, and the percentages are yours to choose.
What pushes a price below its floor
A sale price left on, a bulk edit, rounding, and a bundle whose price was set before a component cost rose. The bundle case is the one a poster in a Shopify thread describes: a bundle missed in the manual updates sells at an incorrect price.
- Check every price against its floor each week.
- Treat a bundle's cost as the sum of its parts.
Alerts first, and your own prices only
Most replies in one thread advise against matching competitor prices automatically; some favour an alert and a hard floor. The CMA case study is a reminder of why: two sellers who agreed not to undercut each other, and used repricing software to carry it out, were found to be a cartel. Set your own prices from your own costs.
Which paid job fits
The floors job works a floor for up to 300 products and builds the checker. The weekly list repeats it.
The proposals job suggests changes inside your floors; you approve each one. None changes a price in your store.
Sources and limits
- Shopify Community: how do you handle it when a competitor undercuts your price Checked 2026-10-12.
- A poster on 15 Aug 2026 says to set a floor from landed cost plus the minimum margin you will accept; another on 17 Aug adds payment fees and expected returns; another on 16 Aug guesses that the alert is more valuable than automation for most.
- GOV.UK (CMA): online sellers price-fixing case study Checked 2026-10-12.
- The CMA case study says two sellers agreed not to undercut each other on a marketplace and used automated repricing software, that the CMA found a cartel and Trod accepted a fine of 163,371 pounds, and that sellers should set their own prices independently of their competitors.
- Shopify Community: Shopify bundles will silently sell at the wrong price Checked 2026-10-12.
- A poster on 5 Sep 2026 says that if a bundle is missed in the manual updates, the bundle will be sold at an incorrect price.