The Price of Choosing How to Pay
A customer chooses a payment method. The order total changes.
At first, that sounds like a simple ecommerce requirement. But when that price difference needs to work consistently across a WooCommerce store, things get a little more interesting.
This was the challenge we faced while working with one of our ecommerce clients.
The client was already offering significant discounts on selected products. These promotions were an important part of their pricing strategy, but there was a problem. Payments made through BNPL providers came with a higher transaction cost for the merchant. That cost couldn’t simply be added to the customer’s bill as a separate BNPL fee. The merchant needed another way to manage the impact.
The answer was to let the promotional discount change depending on the payment method. And that’s where the engineering problem began.
Ecommerce
WooCommerce, AJAX, PHP
5 mins.
The Problem Behind the Requirement
The client’s concern wasn’t really about BNPL itself. It was about margins.
When a product is already heavily discounted, every additional transaction cost matters. A payment method that carries a higher merchant-side fee can make an otherwise viable promotion much less sustainable. The client therefore wanted more flexibility over the promotional discount offered for different payment methods.
For example, a product might receive a larger discount when a customer pays through a standard payment method, while receiving a slightly smaller promotional discount when the customer chooses BNPL.
Importantly, this isn’t the same as adding a BNPL surcharge. The customer isn’t being charged an additional fee for using BNPL. The merchant is simply choosing how much of its existing promotional discount to offer for that payment method.
That distinction shaped the entire solution.
Why We Couldn’t Just Add a Discount
WooCommerce already has plenty of ways to change prices. But this requirement was slightly different. The price needed to depend on something that isn’t known when the customer first visits the product page: the payment method they eventually choose.
A customer might see a product, add it to the cart, proceed to checkout, and only then select BNPL. So the system had to respond when that choice was made. At the same time, the customer shouldn’t have to wonder why the price suddenly changed. We needed to make the pricing clear from the beginning while ensuring that the final checkout price matched the selected payment method.
Making the Price Visible
We started with the customer experience. Payment-specific pricing was presented directly on the product page, allowing customers to see the effective price associated with the available payment methods.
Payment-specific pricing displayed directly on the product page, giving customers visibility into the promotional price available for each payment method.
This was more than a visual feature. The price shown to the customer needed to be calculated using the same rules that would eventually be applied during checkout. That meant the customer could understand the pricing before making a payment decision, rather than discovering the difference only at the final step.
Making It Work in WooCommerce
The next challenge was making the pricing actually work. WooCommerce doesn’t know which payment method a customer will use when the product page loads. That choice happens later, during checkout.
So we built a small custom plugin that connects the selected payment method with the promotional pricing configured by the merchant. When the customer changes their payment method, WooCommerce updates the checkout, and our pricing logic responds accordingly.
The checkout responds to the selected payment method, applying the appropriate promotional discount and updating the order total.
The important part was making the experience feel natural:
- The customer selects a payment method.
- The order updates.
- The applicable promotional price is reflected.
- No manual calculations.
- No coupon codes.
- No confusing additional fees.
Just a price that reflects the payment method selected.
Keeping the Experience Consistent
There was another important consideration.
The pricing shouldn’t behave differently at different stages of the shopping journey. If a customer sees one payment-specific price on the product page but gets an unexpected price at checkout, the system has failed, even if the underlying calculation is technically correct.
So we designed the plugin around a simple principle: What the customer sees should make sense when they reach checkout.
That meant accounting for the product page, cart, and checkout rather than treating payment-specific pricing as a single isolated feature.
Why We Built It as a Plugin
We could have approached the requirement as a collection of custom changes throughout the website. Instead, we built it as a dedicated WooCommerce plugin for WordPress. That gave the pricing functionality its own configuration and made it easier to manage as the merchant’s requirements evolved.
Different payment methods could have different promotional discount rates, without having to create separate product variations or manually maintain different prices across the store. It also kept the feature independent from the website’s theme and other customizations.
A Small Requirement With a Bigger Lesson
This project is a good example of how a seemingly small business requirement can require careful engineering.
The original request was simple: “We need different promotional prices for different payment methods.”
But behind that request were several considerations:
- The merchant needed to protect its margins.
- The payment providers had restrictions around additional customer fees.
- Customers needed to understand the pricing.
- WooCommerce needed to recalculate the order when the payment method changed.
- And the experience needed to remain consistent from product page to checkout.
None of these problems individually were particularly unusual. The challenge was making them work together without making the customer experience complicated.
Engineering Around the Real Business Problem
For us, the most interesting part of this project wasn’t building another discount feature. It was understanding what the client was actually trying to achieve. They weren’t looking for a way to charge customers more for BNPL. They needed a way to make their existing promotional strategy work better with the economics of different payment methods. Once we understood that distinction, the solution became much clearer.
We built a payment-aware pricing system that gives the merchant more control over promotional discounts while keeping the customer experience straightforward. Sometimes, the best engineering solutions aren’t about adding more complexity.
They’re about hiding the complexity from the customer while solving the real problem underneath.
Final Thoughts.
For us, it wasn’t about making BNPL more expensive, or creating another layer of fees for customers. It was about giving the merchant a way to protect the economics of its promotions while keeping the customer experience straightforward. The complexity stays behind the scenes. The customer simply chooses how to pay and sees the price that comes with that choice. That’s the kind of engineering we enjoy building, where a complicated business problem can become a simple interaction.
Let’s Engineer Something Remarkable.
Every digital experience is shaped by hundreds of decisions, from user experience and performance to the engineering that powers every interaction behind the scenes. Great products don’t happen by chance. They emerge through collaboration, curiosity, and a commitment to solving problems with purpose. We believe technology should do more than meet requirements. It should simplify workflows, delight users, and create lasting value for the businesses behind it. Whether you’re launching a new venture or refining an established platform, we’ll help transform your vision into a digital experience that’s intuitive, scalable, and built to grow with your ambitions.
Found this article useful?