QUICK ANSWER
Before Black Friday on 27 November 2026, reconcile your payment processors through the most recent month end, confirm landed cost on the products you plan to discount, check that returns are posting against the product rather than against revenue, and work out the contribution margin on each discounted item. The fourth one sets your discount floor, and without it a record weekend can lose money.
What should I fix in my books before Black Friday?
Four things, and all of them are easier now than in December. Reconcile every payment processor and bank account through your most recent month end, so the baseline you measure November against is real. Confirm landed cost on the products you intend to promote, including freight and duty rather than just the supplier invoice. Check that returns and refunds are posting against the product they relate to rather than being netted against total revenue. Then calculate contribution margin on each item you plan to discount.
The first three are hygiene. The fourth is the one that changes a decision, and it is the one most sellers skip because it takes an hour and feels like finance rather than marketing.
Why does a record November turn into a flat year?
Because revenue and margin move in opposite directions during a discount event, and only one of them is on the dashboard. Contribution margin is what is left from a sale after the costs that move with it: landed cost including freight and duty, the marketplace or payment processing fee, your real blended outbound shipping rate rather than what the customer was charged, the return rate on that specific product, and paid acquisition where the sale was bought rather than earned.
Run that calculation on an item discounted 30% with paid traffic behind it and the answer is frequently negative. Every additional unit sold makes the month worse, and the dashboard shows the best week in the company’s history while it happens. The owner finds out in February, when the year closes and the profit is not where the revenue line said it would be.
What is the lowest discount my product can actually carry?
Work it out per product rather than across the catalogue, because the answer varies more than most owners expect. Take the selling price, subtract landed cost, payment and marketplace fees, your true shipping cost, and an allowance for the return rate on that item. What remains is the contribution before advertising. Subtract your acquisition cost on paid traffic and what remains is what the sale is actually worth.
That number is the discount ceiling for the item. Build the promotion inside it. In practice this usually means discounting the high-margin items harder and protecting the ones that only work at full price, which is close to the opposite of what most stores do. The instinct is to discount whatever is not selling, and whatever is not selling is often the thing with the worst margin to begin with.
One caution on the arithmetic above. A contribution margin calculation is only as good as the landed cost underneath it, and landed cost is the number most stores have never actually built. If your cost of goods is the supplier invoice, freight and duty are missing, and every margin figure in the business is better than reality by whatever those two add up to. On goods sourced from overseas that gap is routinely meaningful. Fix the landed cost first; the discount floor calculated on top of a wrong cost is just a more confident wrong answer.
What do I need to capture while the weekend is happening?
Three things, and they are much harder to reconstruct afterwards. Record your ad spend by channel and by day, because blended monthly figures will not tell you which day paid for itself. Record inventory counts on products that sell out, since a stockout on 28 November is a planning input for next year and nobody remembers it in March. And keep the discount codes mapped to the campaigns that used them, because an unmapped code becomes an unexplained revenue gap in the December close.
The weekend itself runs 27 to 30 November 2026: Black Friday on the Friday, Small Business Saturday on the 28th, and Cyber Monday on the 30th. Returns from it land in December and January, which is the second reason the return rate belongs in your margin calculation now rather than being discovered later.
What does good look like going into December?
Your October books are closed and reconciled, so November has something to be compared against. You know the discount floor on every item in the promotion. Your ad spend is recorded daily rather than monthly. And your November close lands in the first half of December rather than in the new year, which is what makes the year-end work in January survivable.
Transcounts delivers closes on a Day-15 cadence, with 92% landing on time and an average first response of 6.2 hours against a 24 hour target. The figures matter here for one reason: a close that arrives in late January cannot inform a decision about January. Peak season is the clearest demonstration of that, because every number it produces has a short shelf life.
If your last clean month end is August or September, there is enough time to do all of this properly. If you are several months behind, be realistic about the goal. A full catch-up before the weekend is unlikely, and chasing one usually means neither the catch-up nor the promotion gets proper attention. The version that works is a clean October close and accurate landed cost on the products you intend to discount, with the rest dealt with in the new year.
Frequently asked questions
When is Black Friday 2026?
Friday 27 November 2026. US Thanksgiving falls on 26 November, Small Business Saturday on 28 November and Cyber Monday on 30 November.
What is contribution margin and how is it different from gross margin?
Gross margin subtracts cost of goods from revenue. Contribution margin also subtracts the costs that move with each sale: payment and marketplace fees, real shipping cost, returns and paid acquisition. For an ecommerce seller it is the more useful of the two, because those variable costs are a large share of the sale.
Is it too late to fix my books before peak season?
If your last reconciled month end is August or September, there is time. If you are months behind, the realistic goal is a clean October close and accurate landed cost on the products you plan to discount, rather than a full catch-up before the weekend.
How do returns affect my peak season numbers?
Returns from a November promotion arrive in December and January. If they are netted against total revenue rather than posted against the product, the discounted item looks more profitable than it was and you repeat the same promotion next year.
NEXT STEP
Transcounts keeps the books for Canadian Shopify and Amazon sellers, including landed cost, returns and payout reconciliation. The $99 Ecommerce Diagnostic reviews your current books and reports back within seven business days, in time to act before the November weekend. The fee is credited against onboarding.
