Purchase ID Quality Calculator

What the calculator tells you

For one purchase-event extract, it reports missing-ID rows as a share of all rows and repeated-ID rows as a share of nonblank-ID rows. It can also record how many IDs were independently confirmed to represent more than one order. It runs locally and sends no records to an AI provider.

Formulas and assumptions

Total rows = nonblank rows + missing/blank rows. Missing share = missing rows ÷ total rows. Repeated-ID rows = nonblank rows − distinct nonblank IDs; their share uses nonblank rows as the denominator. A percentage is unavailable when its denominator is zero. Confirmed reused IDs cannot exceed the number of distinct IDs or repeated rows. The input does not prove the review is complete.

Try the synthetic example

With 90 nonblank rows, 75 distinct nonblank IDs, ten missing rows and four confirmed reused IDs, the tool shows 100 event rows, 10% missing and 15 repeated-ID rows (16.7% of nonblank rows). The four confirmed IDs are not four lost orders. Use the worksheet to document scope and next checks, then the prompt to draft a note from anonymised totals.

What it cannot tell you

Repeated IDs can reflect a retry or multiple real orders with one key; missing IDs can belong to orders already seen. The result is not a true-order count, financial adjustment, conversion rate or estimate of reporting loss. Leave reuse blank if you have not checked it.

Sources and limits

Checked 3 November 2026: Google's transaction-ID guidance covers purchase deduplication for web streams, including empty-ID and reused-ID risks. Google's diagnostics guide describes missing and non-unique purchase identifiers. Adobe's purchaseID guidance, updated 28 September 2026, documents different product rules. This worksheet is an original review method, not vendor advice or a guarantee of report corrections.