You added a gift-wrap toggle or a "premium material" choice to your product page — but the price never changes at checkout. That's because native Shopify custom fields don't carry a price. Here's how to charge extra for a product option on Shopify, using fixed or percentage add-on pricing that reaches checkout correctly.
Why native custom fields can't charge extra
Shopify's built-in way to collect option input is line-item properties — custom fields you add to the product form in your theme. They're great at capturing text like "Engraving: Sofia," but they have one hard limitation: they add no price.
A line-item property is just a label and a value attached to the order. There's no field for money, so however you build it — gift wrap, rush service, premium fabric — the customer pays the base price and nothing more. To actually charge for an option, the extra amount has to become a real line on the order that checkout can total. That's exactly what an app handles.
The fix: Optionify add-on pricing
Optionify lets you attach an add-on price to any option or value. When a customer selects it, the extra amount is added to their total at checkout. You set this per option in the Option Set Editor, and there are two modes — both live:
- Fixed — a set money amount (e.g. +$5.00 for gift wrap)
- Percent — a percentage of the product's price (e.g. +15% for a premium material)
Set a fixed amount or a percentage of the product price as the add-on charge.
Fixed vs Percent — which to use
Pick the mode that matches how the upgrade should scale:
- Fixed is best for flat add-ons that cost the same regardless of the product: gift wrapping, rush processing, a stamped card. +$5 is +$5 whether the item is $20 or $200.
- Percent is best for upgrades that should scale with the base price: a premium material on a $40 shirt versus a $400 jacket shouldn't cost the same flat fee. A percentage keeps the surcharge proportional.
How the extra charge reaches checkout
This is where a lot of options apps quietly fail. Optionify sends add-on charges to checkout through a hidden companion product — the extra amount rides along as a separate, invisible line so checkout totals it correctly.
The important consequence: it works with Buy it Now and Shop Pay, not just the standard cart. Express and accelerated checkouts skip the cart page, so approaches that only adjust the cart lose the surcharge. The companion-product method means the extra charge is collected wherever the customer checks out.
Every selection and its price also appear on the Shopify order as line-item properties, so your fulfillment team sees exactly what was chosen and what was charged.
How to charge extra for an option, step by step
- Install Optionify — free forever, add-on pricing included
- Enable the Optionify app embed in your theme editor so options render on the storefront
- Click Create option set (or open an existing set in the Option Set Editor)
- Add the option you want to charge for — for example a Switch for gift wrap, or a Radio buttons option for material
- On the option or value, set the add-on price and choose Fixed or Percent
- Choose an assignment: all products, by tag, by collection, or individual products (assignment types)
- Set the set to Active and save via Shopify's save bar
- Use Preview to open an assigned product and confirm the extra charge appears in the total
Use cases: what to charge extra for
Add-on pricing fits any option that adds cost or value:
- Gift wrap — a Switch option that toggles on a flat +$5, perfect for Fixed pricing
- Rush / priority processing — a fixed fee for faster turnaround
- Premium material or finish — a Percent add-on that scales with the product price
- Engraving or embroidery — a fixed fee on top of a text input
- Add-on products or accessories — a fixed charge for a bundled extra
- Size or dimension upgrades — pair with the Dimension type for area-based pricing
For a deeper look at pricing options and how add-on charges behave in the cart and order, see pricing product options.
Does charging extra cost anything?
No. Optionify is free forever, and that includes add-on pricing in both Fixed and Percent modes. There are no paid tiers, no premium plan, and no transaction fees on the extra amounts you collect. You keep what you charge.
FAQ
How do I charge extra for a product option on Shopify?
Native line-item properties add no price. Use Optionify: add an add-on price to any option — a fixed amount or a percentage of the product price — and it's collected at checkout, including on Buy it Now and Shop Pay.
Can I charge a percentage instead of a fixed amount?
Yes. Optionify supports both. Fixed adds a set money amount; Percent adds a percentage of the product's price, useful for premium upgrades that should scale with the base price. Both modes are live.
Does the extra charge work with Shop Pay?
Yes. Optionify sends add-on charges to checkout through a hidden companion product, so the extra amount is collected correctly on express checkouts like Buy it Now and Shop Pay, not just the standard cart.
Get started
- Install Optionify — free
- Learn how option pricing works
- Add a paid gift-wrap toggle with a Switch option
Need help? See the Troubleshooting Guide or contact support.