Pre-event, the week before.
Verify discount configuration. Test orders with each promo code. Confirm pre-tax vs post-tax behavior matches your jurisdiction (UK/EU: pre-tax for trade discounts). Confirm tax calculation per market is current. Verify your gateway can handle the volume: many gateways have rate limits that surface only under load.
Audit inventory levels. Confirm WAC is current per branch. If a SKU was recently restocked, the WAC should reflect the new average. Bundle definitions current. Out-of-stock SKUs hidden or marked accordingly. Run a reconciliation between Shopify stock and Nonari canonical to catch drift before it matters.
- Test discount codes for tax calculation correctness
- Verify gateway rate limits with provider
- Reconcile inventory between Shopify and canonical ledger
- Audit bundle definitions for accuracy
- Confirm fulfillment capacity at warehouses and couriers
During the event, real-time monitoring.
Watch for stock drift. With high velocity, even small sync delays accumulate. If your SKU shows 50 units in Shopify but the canonical ledger says 30, you will oversell. Nonari pushes stock continuously with conflict resolution; verify the dashboard shows green status throughout.
Watch for payment failures. Card declines, 3DS challenges, and gateway timeouts spike under load. Some are legitimate; some are gateway capacity issues. Track the fail rate per minute. If it doubles for more than 10 minutes, escalate to the gateway. A spike that goes ignored is revenue lost.
COD orders during peak.
In COD-heavy markets, Black Friday volumes spike at 5-10x normal. Couriers hit capacity, fulfillment delays grow, and RTO rates often climb to 25-35% in the post-event window because customers oversold their excitement and refused at delivery.
Adjust accordingly: do not post revenue at order, post at delivery confirmation. Pre-allocate inventory for the spike but expect higher RTO. Track RTO per courier per region in real-time so you can shift volume to the most reliable courier mid-event. The accounting flows from the courier delivery report; do not try to recognize revenue based on order placement during peak.
Post-event, the close.
Day 1 post-event: reconcile Shopify payouts. With 5x volume, the payout report is large. Confirm fees, refunds, and chargebacks decompose correctly. Confirm the clearing account balance is reasonable; an unexpected positive or negative balance means something did not flow.
Day 2-3: process refunds and chargebacks. Black Friday generates an above-normal refund rate (buyer’s remorse, wrong items, overordered). Confirm each refund reverses both revenue and COGS at original WAC. Confirm Inventory write-offs for unsellable returns. Chargebacks open in 7-14 days; track them as the second wave.
Discount tracking and margin.
Discount load during Black Friday is usually 15-30% of gross revenue. Track per code so you can see which promos drove what volume. If a sitewide 25% off code captured 60% of orders, your average margin took a 25% hit on those orders. Calculate effective gross margin post-event.
On a typical Black Friday: gross sales $50,000, discounts $12,000 (24%), net sales $38,000, COGS $19,000 (50%), gross margin $19,000 (50% of net or 38% of gross). The 50% gross margin number is the right one for unit economics analysis. Do not confuse it with the headline "$50k Black Friday revenue" number; that is the gross.
Tax filing implications.
A Black Friday week in late November falls in a single filing month. The output tax (VAT, GST, or sales tax) on net sales for that month is significantly above baseline. Make sure your input tax claims are also captured: the inventory you bought to stock for the event, any platform fees with VAT/GST, any marketing spend.
For cross-border Black Friday volume, destination VAT/GST obligations spike too. EU VAT on EUR-denominated sales, UK VAT under MTD, Australian GST. If you are below marketplace facilitator threshold and Shopify is not collecting on your behalf, the obligation lands on you. Scale into Black Friday on cross-border deliberately; do not stumble across a registration threshold mid-event.
Operational debrief.
Within a week, run an operational debrief: total orders, gross revenue, discounts, net revenue, COGS, gross margin, refund rate, RTO rate (if COD), chargeback rate (later), top SKUs, bottom SKUs, top couriers by volume and reliability. Compare to last year’s numbers if available.
The patterns from one Black Friday inform the next: which discount codes drove margin-positive volume, which drove margin-negative; which couriers held up; which products had the worst RTO. Without the debrief, the next Black Friday repeats the same mistakes. The accounting layer is the input to the debrief; without clean books, you are running on guesses.
Where Nonari fits.
Nonari handles peak volume natively. Stock sync continues, payouts auto-reconcile, refunds reverse cleanly, chargebacks track through their lifecycle. The dashboard shows the live picture without you having to assemble it. Per-discount-code margin reports, per-courier RTO rates, per-SKU performance all flow from the same data the GL is built on.
For Shopify merchants spinning up an international storefront for the first Black Friday, the multi-branch setup means books stay clean across markets. USD sales, EUR sales, GBP sales each in their own branch with their own tax accounts. Consolidated reporting in your functional currency with FX isolated. The peak event becomes operationally challenging but accounting-clean, which is the right tradeoff.