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<title>Fix: "A duplicate transaction has been submitted" (Authorize.Net)</title>
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<h1>Quick fix: "A duplicate transaction has been submitted" (Authorize.Net)</h1>
<p>
The duplicate error occurs because Authorize.Net blocks repeated transaction submissions that look identical within a short window (default ~120s).
The easiest, reliable fixes are listed below — use one or more to avoid the E00027 error.
</p>
<div class="steps">
<strong>Short & practical steps:</strong>
<ol>
<li><strong>Attach a unique order id</strong> to every attempt (use <code>order.invoiceNumber</code> or <code>refId</code>). This tells Authorize.Net each retry is a distinct transaction.</li>
<li><strong>Use validation only when needed:</strong> For CVV correction flows, consider <code>validationMode: testMode</code> or do a lightweight <em>authorization-only</em> for validation, then run the real charge after customer confirms details.</li>
<li><strong>Handle the E00027 response gracefully:</strong> If you get E00027, generate a new invoice/refId and re-submit the payment (or prompt the user and retry server-side after short delay).</li>
</ol>
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<p><strong>Example JSON (concept):</strong></p>
<pre>
{
"createCustomerPaymentProfileRequest": {
"merchantAuthentication": {
"name": "YOUR_API_LOGIN",
"transactionKey": "YOUR_TRANSACTION_KEY"
},
"customerProfileId": "12345678",
"paymentProfile": {
"billTo": { "firstName":"John", "lastName":"Doe" },
"payment": {
"creditCard": {
"cardNumber": "4111111111111111",
"expirationDate": "2026-12",
"cardCode": "123"
}
}
},
"validationMode": "liveMode",
"refId": "order-20251003-160920" /* <- make this unique for every attempt */
}
}
</pre>
<p><strong>Server-side retry pseudocode:</strong></p>
<pre>
try {
submitCreateCustomerPaymentProfile(payload);
} catch (err) {
if (err.code === 'E00027') {
// generate a new unique refId/invoiceNumber and retry once
payload.refId = 'order-' + Date.now();
submitCreateCustomerPaymentProfile(payload);
} else {
throw err;
}
}
</pre>
<p class="hint">
<strong>Why this works:</strong> Platforms like Crunchyroll attach unique transaction/invoice IDs to each payment attempt and separate validation from the final charge. That prevents accidental duplicate detection when a user retries with corrected CVV — follow the same pattern to make your flow smooth and user-friendly.
</p>
<p class="hint">
If you want, I can convert the above into a short 2–3 line forum comment (HTML or plain text) you can paste directly into Q&A sites.
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