By Marc Alexander

Black Friday falls on 27 November in 2026 and Cyber Monday on 30 November. For many US stores, those few days decide the year, and they're the worst possible time to find out your tracking is broken.

Problems that cost a little on a normal day cost a lot when traffic and spend are at their peak. Worse, the data from those days is what you'll plan next year's budget with. These are the checks worth doing in October, while there's still time to fix what they find.

Six weeks out: the purchase.

  1. Test a purchase on every payment method. Card, PayPal, Apple Pay, Shop Pay, buy now pay later: each one can take a different route to the confirmation page, and each can break tracking differently.
  2. Check every purchase has a unique transaction ID. GA4 drops repeat purchases with the same ID, so a missing or blank one lets reloads and return visits count twice.
  3. Check revenue is the right figure. Item value without sales tax or shipping, as Google recommends. See US sales tax and shipping in GA4.
  4. Send discount codes. The coupon parameter is the only way GA4 can tell you which offer drove which sales.
  5. Compare a week of GA4 revenue with your store. Know your normal gap now, so a change during the sale stands out.

Four weeks out: campaigns.

  1. Agree UTM names for every sale email, social post and paid campaign. Lowercase, consistent, written down. The UTM builder keeps them tidy.
  2. Check Google Ads conversions. Purchase as the primary conversion, with the same value GA4 records, and nothing like add to cart counted alongside it.
  3. Check consent. Make sure tags respect visitors' choices, including opt-outs and Global Privacy Control where state law requires it. A sale is no time to attract a complaint.
  4. Check page speed with every tag running. Sale banners, countdown timers and extra pixels slow pages down exactly when traffic peaks.

Two weeks out: freeze.

  1. Freeze tracking changes. No new tags, no container clean-ups, no theme updates that touch checkout, until after Cyber Monday.
  2. Publish the final container version and note its number, so you can roll back in one click if something goes wrong.
  3. Write down the dates of every change to site, prices and campaigns, so next year's comparison makes sense.
  4. Check data limits. Standard GA4 properties have a daily limit of 1 million events for the BigQuery export. A busy sale can pass it. Streaming export has no event limit, at a small charge. If you use server-side tagging, check your hosting plan can take the extra requests.

During the sale.

  • Watch Realtime and DebugView, not just sales. Purchases should arrive in GA4 at roughly the rate orders arrive in your store.
  • Set up alerts. A custom insight in GA4, or monitoring that warns when purchases stop, catches a broken checkout in minutes rather than days.
  • Have one person ready who can read the container and roll it back.

Afterwards.

Compare GA4 with your store for the whole period, by day and by payment method. Any gap that grew during the sale is worth explaining before the numbers go into a board report.

Marc Alexander checks ecommerce tracking for US businesses. The GA4 mini audit takes 3 to 5 working days, so there's time to fix what it finds before the sale, and tracking monitoring watches for breaks while it runs.