How to Create a WooCommerce Single Product Checkout Plugin (Step-by-Step)

WooCommerce is powerful, but by default it follows a Cart → Checkout flow.

For landing pages, ads, D2C products, services, bookings, or limited offers, this extra step can reduce conversions.

That’s where Single Product Checkout comes in.

In this blog, we’ll build our own WooCommerce plugin that:

✅ Skips the cart page

✅ Automatically adds a specific product

✅ Redirects users straight to checkout

✅ Locks quantity to 1

✅ Ensures only one product is purchased

All using clean PHP hooks — no third-party plugins.

Why Use Single Product Checkout?

Single Product Checkout is ideal when:

• You sell one flagship product
• You run Facebook / Google Ads
• You use landing pages
• You sell services, tickets, subscriptions
• You want faster checkout & higher conversion

Many premium plugins do this — but as developers, we should control the logic ourselves.

Plugin Architecture Overview

We’ll create a lightweight custom plugin using WooCommerce hooks.

Plugin Responsibilities:

1. Detect product page
2. Check specific product ID
3. Auto-add product to cart
4. Redirect to checkout
5. Prevent other products from being added

Plugin Folder Structure

  
wp-content/
└── plugins/
    └── single-product-checkout/
        └── single-product-checkout.php
   

Only one file is enough.

Step 1: Create the Plugin File

Create this file:

single-product-checkout.php

<?php
/**
 * Plugin Name: Single Product Checkout (Custom)
 * Description: Redirects a specific WooCommerce product directly to checkout.[https://ipdata.in]
 * Version: 1.0
 * Author: Taabeer Ahmad
 */

if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

This header allows WordPress to recognize your plugin.

Step 2: Define Product ID

We must specify which product will use direct checkout.

 
define( 'SPC_PRODUCT_ID', 123 ); // Replace with your product ID

 

How to Find Product ID?

Admin Panel → Products → Hover over product → ID shown

Step 3: Auto-Add Product & Redirect to Checkout

This is the core logic.

add_action( 'template_redirect', 'spc_direct_checkout' );

function spc_direct_checkout() {

    if ( ! is_product() ) return;

    global $post;

    if ( $post->ID != SPC_PRODUCT_ID ) return;

    if ( is_admin() ) return;

    if ( WC()->cart->is_empty() ) {
        WC()->cart->add_to_cart( SPC_PRODUCT_ID );
    }

    wp_safe_redirect( wc_get_checkout_url() );
    exit;
}

 

How This Works:

• Runs before page loads
• Checks if current page is product page
• Matches specific product ID
• Adds product to cart if empty
• Redirects user to checkout

Result:

User never sees the cart page

Step 4: Skip Cart Page Completely

Even if someone clicks “Add to Cart”, we force checkout.

add_filter( 'woocommerce_add_to_cart_redirect', 'spc_skip_cart' );

function spc_skip_cart() {
    return wc_get_checkout_url();
}
  

Step 5: Lock Quantity to 1 (Optional)

Perfect for:

• Services
• Subscriptions
• Fixed-price offers

  add_filter( 'woocommerce_quantity_input_args', 'spc_lock_quantity', 10, 2 );

function spc_lock_quantity( $args, $product ) {

    if ( $product->get_id() == SPC_PRODUCT_ID ) {
        $args['min_value'] = 1;
        $args['max_value'] = 1;
    }

    return $args;
}
 

Step 6: Remove Other Products from Cart

This ensures only one product can be purchased.

 add_action( 'woocommerce_before_calculate_totals', 'spc_remove_other_products' );

function spc_remove_other_products( $cart ) {

    if ( is_admin() && ! defined( 'DOING_AJAX' ) ) return;

    foreach ( $cart->get_cart() as $cart_item_key => $cart_item ) {
        if ( $cart_item['product_id'] != SPC_PRODUCT_ID ) {
            $cart->remove_cart_item( $cart_item_key );
        }
    }
}

Testing Checklist

✅ Activate plugin

✅ Open product page

✅ Redirects to checkout

✅ Quantity locked

✅ No cart page

✅ Payment works

Test with:

• Razorpay
• Stripe
• COD
• PayU

Important Notes

Advanced Customizations (Next Level)

You can enhance this plugin by adding:

URL Based Pricing

  ?price=999
   

Auto-Apply Coupons

  WC()->cart->apply_coupon('WELCOME50');
   

Conditional Checkout Fields

• Hide shipping
• Hide company name
• Hide phone/email

Multiple Product Checkout Pages

Using array of product IDs