⚠️ Shop Pay (Pay in 3) switched checkout to shop.app — broke Meta pixel attribution & tracking

Shopify Discussion
, , ,

Topic summary

Enabling Shop Pay Installments (Pay in 3) silently switches the checkout domain from the merchant’s custom domain to shop.app, breaking Meta pixel attribution and Conversions API tracking.

Impact observed:

  • Purchase events stopped firing correctly for five days
  • Meta’s ad optimizer lost learning data
  • Approximately £175 wasted in ad spend before the issue was identified

Workarounds confirmed:

  • Revert to the original checkout domain and disable Pay-in-3
  • Re-verify shop.app in Meta Events Manager and remap conversions via Conversions API

Core concern: Shopify provides no warning about this domain change when enabling the feature, despite marketing it as a conversion booster. Merchants relying on accurate attribution should verify tracking setup before activation to avoid performance loss and wasted ad budget.

The discussion remains open regarding whether Shopify will add warnings or documentation for this behavior.

Summarized with AI on October 23. AI used: claude-sonnet-4-5-20250929.
1

We’ve just had a major tracking issue after enabling Shop Pay Pay-in-3.

I’ve been on Shopify for 13 years, and last week enabling Shop Pay Installments (Pay in 3) silently changed our checkout domain from brownieheaven.co.uk to shop.app.

This instantly broke our verified Meta pixel domain and Conversions API — no purchase events fired correctly for five days. Meta’s optimiser lost all learning data and we wasted around £175 in ad spend before realising what happened.

We’ve now reverted to brownieheaven.co.uk as the checkout domain and tracking is working again, but this behaviour really needs a clear warning or toggle before it happens.

If you rely on accurate attribution for Meta ads, be aware this domain switch can cost real money and performance.

Has anyone else had the same issue, and can Shopify confirm whether this will be fixed or at least documented?

Thanks,
Jason – Brownie Heaven :chocolate_bar:

(Checkout & attribution integrity shouldn’t break silently after 13 years of loyal trading!)

2

Yes, it’s because Shop Pay Installments takes you through shop.app in checkout, which changes the primary domain and breaks verified tracking. For now, disable the Pay-in-3 option and use the regular Shop Pay option to keep your attribution consistent. Or, re-verify shop.app on Meta Events Manager, and map your conversions over the Conversions API to regain tracking continuity.

3

Yes thanks I did all that I’m just creating a waring and letting other merchants know not to enable it without looking at the attribution first, there is no warning when you add in fact it is sold as it will increase conversions, yet if not handled properly will tank conversions.