Returning customers use offers reserved for new customers

What you see

Verified existing customers redeem an offer whose rules restrict it to first purchases.

Illustration: 15 returning customers redeem an offer reserved for first purchases; customers with unknown status remain separate. — Keep unknown status separate.

Check this first

Join offer redemptions to purchase history as it stood before each redemption.

Data needed

Offer ID, redemption time, discount amount, and order ID
Customer purchase history available at redemption
The offer rules and eligibility settings in effect at that time

Run the check

#1
Confirm the offer’s written eligibility rule and dates.
#2
Match redemptions to complete earlier purchase history.
#3
Separate ineligible redemptions, valid exceptions, and unknown customers.
#4
Inspect offer settings and quantify the actual discount granted to ineligible orders.

Calculate

Ineligible redemption share = verified ineligible redemptions / redemptions with known eligibility. Report unknown eligibility separately. Report actual discounts granted, not assumed recoverable profit.

Compare groups

Offer code
Customer status at redemption
First versus repeat purchase
Discount and product contribution

What a healthy result looks like

Known redemptions follow the offer rule, with documented exceptions and an explicit unknown group.

When to investigate

For a strictly first-purchase-only offer, any verified repeat-customer redemption is a rule exception. Prioritize by affected spend; no arbitrary 5-point increase is needed.

Possible causes

Offer restrictions don't enforce the stated eligibility.
Customer accounts or matching rules allow earlier buyers to appear new.

Rule out these explanations

An authorized exception
Incomplete order history
A recent identity or login change

What to do next

Correct the eligibility rule or its enforcement. Remove misclassified redemptions from first-purchase reporting.

What this check can tell you

The discount granted is observed. The sales or profit that would remain after removing it require a separate estimate or test.

Use this check with AI

Run a read-only check for: Returning customers use offers reserved for new customers.
First confirm the available sources, columns, row grain, date basis, currency, and customer definition. Use only authorized data.
Required inputs: Offer ID, redemption time, discount amount, and order ID; Customer purchase history available at redemption; The offer rules and eligibility settings in effect at that time.
Check: Verified existing customers redeem an offer whose rules restrict it to first purchases.
Calculate: Ineligible redemption share = verified ineligible redemptions / redemptions with known eligibility. Report unknown eligibility separately. Report actual discounts granted, not assumed recoverable profit.
Slice by: Offer code; Customer status at redemption; First versus repeat purchase; Discount and product contribution.
Use this comparison rule: For a strictly first-purchase-only offer, any verified repeat-customer redemption is a rule exception. Prioritize by affected spend; no arbitrary 5-point increase is needed.
Show the source totals, calculation, unknown groups, missing inputs, and result. Don't invent fields, thresholds, customer matches, or causal effects.
Rule out: An authorized exception; Incomplete order history; A recent identity or login change.
Describe the observed signal separately from possible explanations. If the check is incomplete, state the exact data needed.
Make no account or budget changes.

Sources and definitions

Shopify: discount eligibilityInspect the actual offer eligibility configuration rather than assuming the label enforces first-purchase eligibility.Read source