> For the complete documentation index, see [llms.txt](https://docs.ipaygh.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ipaygh.com/integrating-ipay/integrating-ipay-payment-system.md).

# Online and On Mobile

## Overview

This describes into details how to integrate into iPay gateway checkout to collect customer payments from your Website, Web App or mobile App. 

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You can use our re-direct API to process payments from ***MTN Mobile Money, Airtel Money, Vodafone Cash, Tigo Cash, VISA*** and ***MasterCard*** and ***QRs***.
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## Explanation of Terminologies

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**Merchant Key**\
It is a unique key assigned to your account for integration and receiving payments.

:ballot\_box\_with\_check:This can be found on the ***`Getting Started`***page on the left side bar.
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**Invoice ID**\
It is an internally generated transaction invoice id.

:ballot\_box\_with\_check: This is unique for every transaction and not more than 25 characters in length.
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**Success URL**\
The page to which iPay will redirect the user after user completes the iPay checkout process.

:no\_entry: **Please note that this does not mean that payment has been received!**
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**Cancel URL**\
The URL your customers should be taken to when they cancel their payment.
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**IPN URL (Instant Payment Notification)**\
This specifies the URL to which iPay will send notification once payment is received.

:no\_entry: Please note the IPN notification from iPay is not confirmation of a payment. Rather it is a prompt that an event of interest has happened to one of your invoices.
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