DupeGuard

Discount abuse protection for Shopify

The same shopper, four times, at your expense.

Shopify checks “one per customer” by email address alone. A plus-sign, a stray dot, a throwaway inbox — and your first-order discount goes out again. DupeGuard finds the person behind the addresses.

Free audit of your recent orders. No credit card.

How it works

Install, see your number, then decide.

Nothing changes in your store until you say so.

Install and see your number

DupeGuard scans your recent orders straight away and shows a dollar figure: how much of your one-time discount went to the same shopper more than once. That runs before you configure anything, and it’s free.

Set your rules

Choose which discount codes are protected and how strict to be. Leave DupeGuard watching quietly, have it flag orders for you to review, or let it turn repeat claimants away at checkout.

Check the flags it raises

Every flagged order comes with the reason in plain language and the evidence behind it, so you can agree or overrule it in seconds. Cancelling an order automatically is a separate switch that stays off until you turn it on.

What it catches

Past the email address, to the person.

Aliases

Plus-signs and dots

you+1@gmail.com and j.smith@gmail.com are the same inbox as far as Gmail is concerned — but four brand-new customers as far as Shopify is concerned.

Throwaways

Disposable inboxes

Temp-mail addresses exist to be used once and abandoned. DupeGuard recognises the domains they come from.

Addresses

One doorstep, many names

The same street address turning up under slightly different spellings, with different emails attached to each order.

Safeguard

Roommates stay safe

A shared address on its own never links two accounts. DupeGuard needs more than one independent signal before it treats people as the same shopper — and you can split or allow any household by hand.

Straight answers

What DupeGuard does not do.

Worth knowing before you install, rather than after.

It doesn’t stop every checkout in advance. Turning a shopper away live at checkout only works for someone signed in to a customer account who DupeGuard has already linked to an earlier claim. A guest checkout, or a brand-new address used for the first time, is caught right after the order lands — flagged for you within moments, not blocked beforehand.

It reads roughly your last 60 days. That’s the window Shopify’s standard permissions expose, so it’s the window the free audit covers. The app says so on screen rather than implying it has read everything.

It isn’t fraud screening. DupeGuard is about discount abuse — chargebacks and stolen cards are a different problem and a different kind of tool.

Pricing

Start free. Pay when you want it to act.

Plans are based on order volume, and DupeGuard recommends one from your real numbers rather than asking you to guess.

Free

$0

Your audit figure, ongoing detection, and the flags it raises — so you can see what’s happening. No card.

Starter

$19 /mo

Under ~100 orders a month. Adds enforcement: turn repeat claimants away, and optional auto-cancel.

Growth

$79 /mo

Roughly 100–500 orders a month, with regular discount campaigns.

Scale

$199 /mo

Above ~500 orders a month. Same enforcement at volume, cancel any time.

See your number first. Decide after.

DupeGuard installs from the Shopify App Store and runs its audit before you configure anything.

Listing pending review — this page will link straight to the App Store once DupeGuard is published.