One page checkout in 1, 2 or 3 columns with a sticky summary, one screen for every field and a safe fallback to the standard checkout.
Tested on 3 buildsUpdated Oct 31, 2026Version 1.0.0CS-Cart, Multi-Vendor 4.17.2 – 4.21.x No core file edits
Built for
One Step Checkout: overview1 of 12
What it does
For CS-Cart and Multi-Vendor stores that want a shorter, cleaner checkout without giving up the core one. Choose three columns, two columns or one narrow column and drag the checkout blocks where you want them. One screen lists all contact, shipping and billing fields with show, hide, required, order and width. The core blocks, form and order placement stay in place, so the add-ons you already use keep their place on the page. Multi-Vendor orders with several vendors get a summary grouped by vendor.
How it works
Install, set Preview link only, and open the preview from Design, One Step Checkout. Pick a layout, drag blocks, and set fields on the Fields tab. Tick any payment method that needs the standard page: customers who choose it switch to the standard checkout with that method selected and their typed data kept. When you are happy, set the page to Everyone. Tested with real orders on offline payment methods; online gateways were not run, so try yours in Preview first.
Features
Three layouts in one license: three columns, two columns or one narrow column
Drag checkout blocks between columns, blocks of other add-ons included
One screen for every field: show, hide, required, optional, order and width
Order summary that stays in view, with Place order and quantity buttons
Phone flow: closed summary at the top, bottom bar with total and Place order
Promo code box and order note stay closed until needed
Typed data survives a reload, and a deleted note stays deleted
Optional first and last name inputs, and no address for carts that need no shipping
Multi-Vendor summary grouped by vendor with each vendor's shipping method
Per-payment fallback, link to the standard checkout and Preview mode; no core changes
What you get
Package
kv_one_step_checkout-1.0.0.zip, installed through Add-ons → Manage add-ons
Updates & support
12 months included. Download new versions from your account and install them in Add-ons → Manage add-ons or the Upgrade Center.
License
1 production installation. Staging, dev and localhost are free and unlimited. The add-on keeps working after the update period ends. How licensing works
For developers
Uses 7 CS-Cart PHP hooks. No core files are changed.
Compatibility
We list only the builds we install and test on. “Tested” means the full test plan was run on that build; “Supported” means the build is inside the supported range and uses the same hooks.
CS-Cart version and edition compatibility
CS-Cart version
CS-Cart
CS-Cart Ultimate
Multi-Vendor
Multi-Vendor Ultimate
4.22 and later
Testing next
Testing next
Testing next
Testing next
4.21.2
Supported
Supported
Supported
Supported
4.20.x
Supported
Supported
Supported
Supported
4.19.x
Supported
Supported
Supported
Supported
4.18.x
Supported
Supported
Supported
Supported
4.17.2
Tested
Supported
Tested
Supported
Before 4.17.2
Not supported
Not supported
Not supported
Not supported
Last tested build: Multi-Vendor 4.17.2, Oct 31, 2026Tested on: Multi-Vendor 4.17.2, CS-Cart 4.17.2
Requirements
Platform
CS-Cart or CS-Cart Multi-Vendor 4.17.2 – 4.21.x
PHP
PHP 7.4 – 8.3 (as supported by your CS-Cart version)
Requirement
The standard Lite checkout page (the default in these versions)
Core changes
None. Hooks and template overrides only
1.0.0
Oct 31, 2026
Latest
Added 9
Three layouts: three columns, two columns, one column, with a block board to move checkout blocks between columns.
Field rules on one screen: show, hide, required, optional, order and width for contact, shipping and billing fields.
Order summary that stays in view, with product images, quantity buttons and a Place order button.
Phone flow: closed summary at the top and a bottom bar with the total and Place order.
Promo code box and order note closed until needed.
Typed values come back after a reload, in that browser tab; a deleted note stays deleted.
Optional first and last name inputs; optional skip of the shipping address when nothing needs shipping.
Multi-Vendor summary grouped by vendor with each vendor's shipping method.
Payment method fallback to the standard checkout, a link to the standard checkout, and Preview mode.
Tested on Multi-Vendor 4.17.2, CS-Cart 4.17.2. First release.
Where do I enter my license key?
On the add-on's License tab, or enter your CS-Cart Marketplace license number in Add-ons > Manage add-ons.
What happens if the license expires or is not valid?
Customers get the standard CS-Cart checkout again with your own field setup, and your layout, field and payment settings are kept. After the update period the add-on keeps working; only updates and support stop.
Can I use one license on several stores?
One license covers one CS-Cart installation. Subdomains of the licensed domain are included.
Do development copies need a license?
No. Development and staging hosts (localhost, *.test, dev., staging. subdomains) never need a license.
Add a released add-on to this order and save 15% on it. It uses the same edition and store domain.
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Buy with confidence
What stands behind your license
Tested builds
Every release is installed and run on these versions before it ships.
CS-Cart4.17.2
Multi-Vendor4.17.2
Multi-Vendor4.21.2
12 months of updates
Updates and support are included in the price. The product keeps working afterwards; renewing is optional.