Buy X get Y, cheapest or N-th item free, tier tables and happy hours inside the CS-Cart promotion editor.
Available Updated Oct 22, 2026Version 1.0.0CS-Cart, Multi-Vendor 4.17.2 – 4.21.x No core file edits
Built for
Advanced Promotions: Buy X Get Y, Tiers, Schedules: overview1 of 14
What it does
Advanced Promotions adds the offers shoppers know from big retailers to the promotion editor you already use. Buy 2 get the cheapest free, every third item half price, buy a camera and get the bag at 30% off, 10% off from 3 items and 15% from 5, lunch-hour deals on weekdays, 20% off everything except sale items, at most three uses per customer. One add-on instead of one add-on per condition. For CS-Cart and Multi-Vendor stores of any size.
How it works
Open Marketing, Promotions, add a cart promotion and pick the new conditions and bonuses next to the core ones. Choose the products, categories or vendors, the quantities and the discount. Core coupons, dates, priorities and the stop other rules option keep working. In the cart, checkout and order details each line shows a short note such as Buy 2, get the cheapest free: 1 x free. On Multi-Vendor every vendor suborder gets exactly its share. Pages stay cache-friendly.
Features
Buy X get Y from the same set or another set, free or discounted, repeatable, with a limit
Cheapest item free, most expensive first or every N-th item discounted
Tier table by quantity or spend: percent off, amount off each item or amount off the total
Discount on a product set: percent, fixed price per item or amount off the set
Product sets by products, categories with subcategories and Multi-Vendor vendors
Exclusions: products, categories, vendors, already discounted items, sale items
Day and time windows, including windows past midnight
Products from a set condition: quantity or subtotal of matching items
Uses per customer, by account or e-mail
Discount cap per promotion
Exact cents: line discounts with taxes, coupons, currencies and Multi-Vendor suborders handled
What you get
Package
kv_advanced_promotions-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 5 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
Tested
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 4.21.2, Oct 22, 2026Tested on: CS-Cart 4.17.2, Multi-Vendor 4.17.2, Multi-Vendor 4.21.2
Requirements
Platform
CS-Cart 4.17.2 – 4.21.x, or CS-Cart Multi-Vendor 4.17.2 – 4.21.x
PHP
PHP 7.2.5 – 8.3, as supported by your CS-Cart version
Platform
Tested on CS-Cart Ultimate 4.17.2, Multi-Vendor 4.17.2 and Multi-Vendor 4.21.2
Theme
A storefront theme based on Responsive (Responsive, Bright, Nova and most third-party themes) for the cart notes
Platform
A license key from cs-cart.kaviolabs.com or a CS-Cart Marketplace license number
Core changes
None. Hooks and template overrides only
1.0.0
Oct 22, 2026
Latest
Added 8
Cart promotion bonus "Buy X get Y (cheapest or N-th item)": same or another set, free / percent / amount / fixed price, cheapest or most expensive first, repeat, limit and cap.
Cart promotion bonus "Tiered discount": up to six quantity or subtotal steps, percent off, amount off each item or amount off the total.
Cart promotion bonus "Discount on a product set" with exclusions and a cap.
Conditions "Day and time" (weekdays and time windows, also past midnight), "Products from a set" (quantity or subtotal) and "Uses per customer".
Product sets by products, categories with subcategories and Multi-Vendor vendors; exclusions for products, categories, vendors, already discounted items and sale items.
Exact money math: line discounts in minor units, remainders to the order discount (or rounded per unit), taxes on the discounted price, exact Multi-Vendor suborder split.
Discount notes per line in the cart, checkout, customer order details and admin/vendor order details; settings to show or hide them.
Domain-bound license check with the License card, badge and Check now; self-healing upgrades (Upgrade synchronizer).
Tested on CS-Cart 4.17.2, Multi-Vendor 4.17.2, Multi-Vendor 4.21.2. First release.
Does it replace the CS-Cart promotions?
No. It adds conditions and bonuses to the core cart promotions. Everything else (coupons, dates, priorities, user groups, storefronts, Stop other rules, reports) is the core.
Does it work with catalog promotions?
The new conditions and bonuses are for cart promotions, so prices on product pages stay cache-friendly. Catalog promotions keep working and run first; use Skip items that already have a discount to keep them from stacking.
Does it work with Multi-Vendor?
Yes. Product sets can include and exclude vendors, and the discount of a checkout is split exactly over the vendor suborders. With Direct Customer-to-Vendor Payments each vendor's cart is calculated on its own.
Which CS-Cart versions are supported?
CS-Cart and Multi-Vendor 4.17.2 – 4.21.x on PHP 7.2.5 – 8.3 (as your CS-Cart version supports).
Why is there an order discount of $0.01?
A discount that does not split evenly over the units of one line (one free item out of three at $16.97) leaves a remainder of a cent or two. With Cents of line discounts = Exact order total it is added to the order discount so the total is exact. Choose Round per unit if you prefer no order discount line.
Are taxes calculated on the discounted price?
Yes, in both tax calculation methods: the discount is part of the line price, like a core product discount.
Can a customer stack a coupon with a Buy X get Y offer?
Yes, unless the promotion uses Stop other rules. The coupon's order discount is calculated on the already discounted subtotal.
Will it slow down my store?
No. The add-on works inside the core promotion calculation, without own tables or remote calls, and prints nothing on cacheable pages.
How do I get updates?
Updates are free during your updates and support period (12 months, extendable). Download the new version from your account on cs-cart.kaviolabs.com or install it from the Upgrade center, and upload it over the installed one. Settings and promotions are kept.
What happens without a valid license?
Without a valid license (no key after the 14-day start period, an invalid or revoked key, a domain the license does not cover, or no successful check for 14 days), promotions that use the Advanced Promotions conditions or bonuses stop applying to new carts. Core promotions, the promotion editor and placed orders are not changed. Once the license is valid again, everything is back.
The admin panel shows a license notice.
Open Add-ons → Manage add-ons → Advanced Promotions: the License card at the top says what is wrong. Fix it on the License tab and click Check now. See License.
Does the add-on work on my staging copy?
Yes. Subdomains of your licensed domain and local development hosts (localhost, private IP addresses, .local, .test) are covered by the same license.
What happens if your license server is down?
Nothing changes for 14 days: the add-on keeps working and retries every hour. Only if no check succeeds for 14 days is it switched off until the next successful check.
Does the license check slow down my storefront?
No. The check runs only in the admin panel or from cron, at most once a day, never while customers browse or check out.
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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