Currency conversion timing
When events arrive in different currencies, analytics converts each to the property's reporting currency using an exchange rate tied to a date. Which date — event day, processing day, prior-day rate — determines the converted total, so the same orders can sum to different revenue depending on timing. This page explains how currency-conversion timing affects revenue figures and reconciliation.
Why the rate date matters
A property has one reporting currency. When an event carries a value in another currency, the tool multiplies by an exchange rate to express it in the reporting currency. Exchange rates move daily, so the converted amount depends on which date's rate is applied — the day the event occurred, the day it was processed, or a previous day's published rate. GA4 applies a rate based on the day before the event, per its documentation.
Because rates differ by date, the same set of orders converts to different totals under different rules.
- Reporting currency requires converting other currencies
- Rates move daily, so the date chosen sets the amount
- GA4 uses the rate from the day before the event
Reconciling revenue
When analytics revenue disagrees with a billing or ledger system, check whether the difference is a currency mix converted at a different rate or date rather than missing orders. Where possible, store the original value and currency so you can recompute under any rule, and reconcile in original currency first to isolate conversion effects. Note that a missing currency field can leave value unconverted entirely.
This is a valuation-timing issue, separate from conversion counting or de-duplication.
How it appears in analytics and logs
Converted revenue that drifts from source-of-truth totals usually reflects the exchange-rate date used, not miscounted orders.
Diagnostic use case
Reconcile revenue that differs from a billing system by accounting for which exchange-rate date analytics used to convert each currency.
What WebmasterID can help detect
WebmasterID records the original transaction value and currency, so you can re-derive totals under a rate date you choose.
Common mistakes
- Comparing converted revenue to billing without aligning rate dates.
- Discarding the original value and currency.
- Blaming order counts for a currency-conversion gap.
Privacy and accuracy notes
Currency conversion operates on transaction values, not visitor identity. This page is educational, not legal advice.
Related pages
- Currency and locale mismatches
Revenue breaks when monetary events mix currencies or send locale-formatted strings. A value like "1.234,56" (European format) or "$1,234.56" is not a number GA4 can sum, and reporting many currencies without per-event ISO codes makes totals meaningless. GA4 converts to a property base currency only when each event carries a valid currency. This page covers currency and locale formatting faults.
- Missing currency or value on events
GA4 monetary events such as `purchase` need both a `value` and a `currency` field, and currency must be a valid ISO 4217 code. If currency is missing or invalid, GA4 may not credit the revenue; if value is missing, the event records but contributes nothing to monetary metrics. This page explains the requirement and the silent failure modes.
- Duplicate transactions in ecommerce data
Duplicate transactions occur when one purchase is counted more than once — usually because the order-confirmation page is reloaded, bookmarked, or shared, or because a retry resends the same event. GA4 deduplicates ecommerce purchases on `transaction_id`, so an absent or unstable ID is the root cause. This page covers detection and the deduplication key.
- Attribution analytics
Re-derive revenue under a rate date you control.
Sources and verification notes
Last reviewed 2026-06-24. Facts are checked against primary/official sources where available; uncertain specifics are marked “Data not yet verified” rather than guessed.