Transaction ID explained — the stable, unique order identifier that prevents purchases from being double-counted on reload.
By The Ad Spend
Updated July 22, 2026.
A transaction ID is the non-sensitive unique identifier assigned to an order, payment or other business transaction.
Why it matters
Purchase pages can reload, API calls can retry and order values can be corrected. A stable transaction ID lets the platform and internal team recognize the same transaction rather than counting each delivery as a new sale.
How it works across ad platforms
Platform or system
Current treatment
Google Ads
Transaction ID is supported in website conversion tags to reduce duplicate purchase conversions.
Microsoft Advertising
Transaction ID supports offline and UET CAPI restatement/retraction behavior.
Pinterest
Order/event identifiers support purchase traceability and duplicate handling.
Meta
Order ID can be custom data while event_id handles Pixel/CAPI deduplication.
TikTok
Use current order/event identifier fields in Purchase payload.
Reddit
Use current conversion/product metadata and deduplication identifier.
LinkedIn
Use current source schema for event/order identifiers.
Implementation rules
Use the source order ID or a stable surrogate.
Do not put personal data in the ID.
Keep it identical across reloads and retries.
Define how refunds, cancellations and partial changes are represented.
Send one currency/value definition consistently.
Common mistakes
Generating a random ID at page load.
Reusing the same ID for recurring orders.
Sending invoice number before it is finalized and then changing it silently.
Technically verified: July 22, 2026. This reference uses official platform sources only for platform-specific behavior. Definitions and implementation recommendations are editorial synthesis by The Ad Spend.
