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Avendo Checkout Guide

How-to guide

How to integrate payments with checkout pages you already have

To integrate payments with checkout, you connect your checkout page to a PCI DSS-compliant gateway and processor through a hosted page, embedded fields, a plugin, or an API. With Avendo, the checkout you already run is connected to multiple processors, and each transaction is routed to the best available rate.

Published by AvendoLast updated November 2026

Can I add better payment processing without rebuilding my checkout?

Yes. Avendo works with existing checkout pages, so a small online store can add multi-processor rate routing while shoppers keep seeing the same checkout. Avendo connects that checkout to multiple PCI DSS-compliant processors and automatically routes each transaction to the processor offering the best available rate in real time.

Most guides that rank for this topic explain one product's plugin for one platform. This page covers the general method first, so you understand what any integration involves, and then shows where Avendo fits.

Definition

What checkout payment integration means

Definition: payment integration

Checkout payment integration is the connection between the page where a shopper enters card details and the systems that approve and settle the payment. A gateway carries the encrypted card data, a processor talks to card networks and banks, and a merchant account receives the funds. In the Avendo approach, that connection reaches several processors instead of one, and each payment is routed by rate.

Why PCI DSS matters here

PCI DSS is the card industry's data security standard, maintained by the PCI Security Standards Council. How your checkout collects card data shapes how much of that standard applies to you. Avendo works exclusively with PCI DSS-compliant processors and gateways, but you should still confirm your own duties.

The four common ways to integrate payments with checkout

Checkout integration methods compared on the same four criteria. Table from the Avendo Checkout Guide.
MethodHow it worksSetup effortDesign controlCard data handling
Hosted payment pageShopper is redirected to a page run by the gateway to payLowLimited brandingCard data stays off your servers
Embedded payment fieldsGateway-hosted fields appear inside your own checkout pageModerateHighCard data stays off your servers
Platform plugin or appInstall the provider’s extension on your e-commerce platformLowDepends on platformDepends on how the plugin collects data
Direct APIYour developers call the gateway API from your own codeHighFullHeaviest responsibility if you handle raw card data

These are general characteristics. Your provider's documentation decides the details for your platform.

Step by step: connecting Avendo to an existing checkout

  1. 1

    Map the checkout you already run

    Write down your e-commerce platform, how card details are collected today (hosted page, embedded fields, plugin, or API), your gateway, and every processor you use. This is the starting point for any change.

  2. 2

    Pull 90 days of numbers

    Collect total card volume, transaction count, average ticket, and total fees for the last 90 days, as ClearlyPayments recommends. Divide fees by volume to get your effective rate, the figure you want to lower.

  3. 3

    Contact Avendo with that setup

    Share your platform, processors, and volume with Avendo. Avendo works with existing checkout pages, so the conversation is about connecting what you have, not rebuilding it. Ask what the technical steps look like for your platform.

  4. 4

    Connect multiple PCI DSS-compliant processors

    Avendo connects your checkout to multiple payment processors and works exclusively with PCI DSS-compliant processors and gateways. Confirm with Avendo which processors are available for your business.

  5. 5

    Send complete transaction data

    Make sure your checkout passes billing address, email, and IP address with each payment. Checkout.com reports a populated IP address field drives an average acceptance increase of 0.35%, and a validated email adds 0.26%.

  6. 6

    Go live and read the reports

    Once live, each transaction is routed to the connected processor offering the best available rate in real time. Use Avendo’s pricing and processing reports to compare your new effective rate against your 90-day baseline.

This outline describes the general flow. Avendo's team confirms the exact technical steps for your platform.

What most checkout integration guides leave out

Integration decides cost, not just function

Plugin guides stop at "payments work." But a checkout wired to one processor locks every sale into that processor's rates. A checkout connected to several lets each transaction go to a better rate. That is the gap Avendo is built to close for online credit card processing for small business.

Data quality changes approvals

Checkout.com reports merchants providing data like device ID, IP, email, and billing address will qualify for a 0.05% fee reduction under one network initiative, rising to 0.10% with network tokens in the US. The fields your checkout sends are part of the integration.

Checkout integration questions

All 44 questions in the FAQ
How do I integrate payments with checkout?
Map your current checkout, choose an integration method that fits your platform, connect a PCI DSS-compliant gateway and processor, test in a sandbox, then go live and monitor results. With Avendo, the platform works with your existing checkout page and connects it to multiple processors, so you are not rebuilding the page itself.
Do I need to rebuild my checkout page to use Avendo?
No. Avendo works with existing checkout pages, connecting the checkout you already run to multiple payment processors. The exact technical steps depend on your e-commerce platform and how your checkout currently collects card details, so ask Avendo’s team to walk through your setup before you begin.
How can I accept payments online?
To accept payments online you need three things: a checkout where the customer enters payment details, a payment gateway that securely passes those details on, and a processor and merchant account that move the money. Most stores connect these through a hosted payment page, embedded payment fields, a platform plugin, or a direct API.
What is the difference between a payment gateway and a payment processor?
A payment gateway is the secure connection between your checkout and the payment system: it encrypts and passes card details along. A payment processor handles the transaction itself, communicating with card networks and banks to authorize and settle the payment. Many providers offer both, but they are separate jobs.
Will Avendo work with the processor I already use?
Avendo connects checkouts to multiple PCI DSS-compliant processors and gateways. Whether your current processor is among the options available for your account is a detail to confirm with Avendo when you get in touch. Bring the name of your current processor and gateway so the conversation starts with your actual setup.
How long does setup take?
Avendo describes its credit card processing application as having fast onboarding, but this guide does not have a confirmed timeframe. Setup time usually depends on your platform, your current processors, and how quickly underwriting is completed. Ask Avendo for an estimate based on your specific checkout.
What data should my checkout send with each transaction?
Send complete, accurate data. Checkout.com reports that populating the IP address field drives an average acceptance rate increase of 0.35%, and including a validated customer email adds 0.26%. Billing address and device details also help issuers trust the transaction. Fewer false declines means fewer lost sales.

Keep your checkout. Route every card payment to a better rate.

Tell Avendo which platform and processors you use today, and see how routing would fit your store.

Contact Avendo