# What's a reasonable QA budget or time allocation, as a percentage of total dev time, for checkout testing on a mid-market Shopify Plus store?

Reviewed by Martin Dejnicki, Director of SEO & AI Search · facts verified October 8, 2026 · canonical: https://deploi.ca/shopify/faq/checkout-qa-budget-percent-of-dev-time

## Short answer

Checkout quality assurance (QA) is budgeted by test matrix, not as a percentage of development hours. No published benchmark sets a defensible checkout QA share: the public highlights of the World Quality Report 2025-26 carry none ([Capgemini](https://www.capgemini.com/insights/research-library/world-quality-report-2025-26/), October 2026). So count combinations to prove: payment methods × discount stacking × tax and duty × customer type × market × fulfillment.

- **Published checkout QA benchmark:** None. The public highlights of Capgemini's World Quality Report 2025-26 carry no QA share of budget, and the full report is gated ([Capgemini, World Quality Report 2025-26](https://www.capgemini.com/insights/research-library/world-quality-report-2025-26/); [OpenText, World Quality Report 2025: AI adoption surges in Quality Engineering, but enterprise-level scaling remains elusive](https://www.opentext.com/about/press-releases/world-quality-report-2025-ai-adoption-surges-in-quality-engineering-but-enterprise-level-scaling-remains-elusive))
- **B2B carts:** No subscriptions, pre-orders or try before you buy. Shopify: B2B doesn't support purchase options, so prune those cells and keep one negative test that a B2B cart cannot take a selling plan ([Shopify developer docs, Apps and B2B](https://shopify.dev/docs/apps/build/b2b))
- **Subscription orders:** No order edits API, no draft orders. Shopify: the order edits API doesn't support subscriptions, and subscriptions can't be used with draft orders, so add cells proving support can correct one without either tool ([Shopify Help Center, Considerations and payment gateways for subscription products](https://help.shopify.com/en/manual/products/purchase-options/subscriptions/considerations))
- **Shopify Scripts deactivated:** 30 June 2026. Shopify deactivated every Script still published and names Shopify Functions as the replacement, so each rebuilt discount, shipping or payment rule needs its own test cells ([Shopify Help Center, Shopify Scripts and the Script Editor app](https://help.shopify.com/en/manual/checkout-settings/script-editor))

## Deploi's call

Refuse the percentage. Ask for the test matrix and the cell count, and pay for that. A percentage of dev hours is a proxy for effort that has no causal link to checkout risk.

**BUILD: Fund a full checkout test matrix when**

- Your discount, shipping or payment rules run as Shopify Functions, which Shopify names as the replacement for the Shopify Scripts it deactivated on 30 June 2026 ([Shopify Help Center](https://help.shopify.com/en/manual/checkout-settings/script-editor), October 2026).
- You sell business-to-business (B2B) or subscriptions, whose Shopify rules add and remove cells ([shopify.dev](https://shopify.dev/docs/apps/build/b2b), October 2026).
- You sell in more than one market or currency, so each payment and discount case runs once per market.
- Two or more apps place blocks in checkout. Deploi's conflict-debugging record scores an app register, a runbook and a synthetic checkout monitor BUILD once two apps touch the same surface ([Deploi decision record](https://deploi.ca/shopify/build-vs-buy/checkout-extension-and-theme-app-conflict-debugging), October 2026).

**WAIT: Keep the matrix small when**

- You sell in one market and one currency, with cards and Shop Pay only.
- You sell no subscriptions and no B2B.
- No two apps touch checkout, which is when Deploi's conflict-debugging record scores the monitor WAIT ([Deploi decision record](https://deploi.ca/shopify/build-vs-buy/checkout-extension-and-theme-app-conflict-debugging), October 2026).

## Why doesn't a percentage of development time work for checkout QA?

A percentage of development time doesn't work for checkout quality assurance (QA), because checkout risk comes from the number of states a customer can reach. That number has almost no relationship to how many hours went into building the storefront. A simple theme with five payment methods across four markets needs far more checkout QA than an elaborate theme selling one product domestically. So the QA line on [a Shopify Plus migration quote's six line items](https://deploi.ca/shopify/faq/shopify-plus-migration-quote-line-items) should be priced from a count of test cases, not from the development total.

## Is there a published benchmark for checkout QA as a share of budget?

No published benchmark sets checkout quality assurance (QA) as a share of development time or budget. Capgemini's World Quality Report, now in its 17th edition, is the long-running industry survey of software testing. Its 2025-26 public highlights cover generative AI adoption, automation barriers, synthetic data, skills and production data, with no QA share of budget ([Capgemini](https://www.capgemini.com/insights/research-library/world-quality-report-2025-26/), October 2026). The full report sits behind a registration form, and OpenText's November 2025 announcement of it carries no budget figure either ([OpenText](https://www.opentext.com/about/press-releases/world-quality-report-2025-ai-adoption-surges-in-quality-engineering-but-enterprise-level-scaling-remains-elusive), October 2026). Earlier editions, through 2017, put testing at 18% to 35% of total information technology (IT) budget ([Capgemini's 15-year review](https://www.capgemini.com/insights/expert-perspectives/15-years-of-world-quality-report-a-journey-in-quality-engineering-and-testing/), October 2026). That share is neither checkout-specific nor a share of development time. In Deploi's search, figures that put QA at 20 to 25% of development do not trace to a checkout-specific source either. So Deploi will not quote a number it cannot stand behind.

## What does a checkout test matrix count?

A checkout quality assurance (QA) test matrix counts every combination of six axes that a mid-market Shopify Plus store must prove works. Build the matrix, count the cells and cost each one, so every line of the QA budget traces to a test.

**Six axes define a mid-market Shopify Plus checkout test matrix (Deploi's checklist)**

| Axis | Values to enumerate |
| --- | --- |
| Payment method | Shopify Payments cards, Shop Pay, PayPal, Apple Pay and Google Pay, gift card, manual or offline |
| Discount state | None, automatic, code, automatic and code stacked, free shipping, at the threshold |
| Tax and duty | Domestic tax, tax-exempt customer, duties-inclusive international |
| Customer type | Guest, logged in, business-to-business (B2B) company contact, subscriber |
| Market and currency | One value per active market |
| Fulfillment | Standard shipping, local pickup, split shipment, pre-order |

Multiply the axes, then prune the combinations that cannot co-occur. What is left is a countable number of scenarios, each a real test with a real cost. That number is defensible in a budget conversation in a way a percentage never is.

## Which Shopify rules add or remove cells in the matrix?

Four Shopify rules add or remove cells in a checkout quality assurance (QA) matrix: Scripts rebuilt as Functions, business-to-business (B2B) purchase options, subscription order limits and Managed Markets exclusions.

- **Scripts rebuilt as Functions.** Shopify deactivated every Shopify Script still published on 30 June 2026 and names Shopify Functions as the replacement ([Shopify Help Center](https://help.shopify.com/en/manual/checkout-settings/script-editor), October 2026). Each discount, shipping or payment rule rebuilt as a Function adds its own test cells. [Which checkout deadlines hit which plans](https://deploi.ca/shopify/faq/checkout-liquid-shutdown-all-plans-or-plus-only) is its own answer.
- **B2B purchase options.** "B2B doesn't support purchase options, such as subscriptions, pre-orders, and try before you buy" ([shopify.dev](https://shopify.dev/docs/apps/build/b2b), October 2026). Prune those cells, then keep one negative test: a selling plan on a B2B cart returns "Only one-time purchase is available for B2B orders" ([Shopify Community](https://community.shopify.com/t/wrong-selling-plan-error-only-one-time-purchase-is-available-for-b2b-orders/387594), thread opened January 2025).
- **Subscription order limits.** Shopify's order edits application programming interface (API) doesn't support subscriptions, and subscriptions can't be used with draft orders ([Shopify Help Center](https://help.shopify.com/en/manual/products/purchase-options/subscriptions/considerations), October 2026). So add cells proving support can correct a subscription order without either tool.
- **Managed Markets exclusions.** Shopify Managed Markets supports neither B2B orders nor subscriptions ([Shopify Help Center](https://help.shopify.com/en/manual/international/managed-markets/requirements-and-considerations), October 2026), so those cells come out of every international market. Its duties-inclusive prices change what the buyer sees, so test the display, not just the calculation; [how Managed Markets fees reach international prices](https://deploi.ca/shopify/faq/multi-market-setup-cost-shopify-plus-quote) is its own answer.

## What should a checkout QA phase deliver?

A checkout quality assurance (QA) phase should deliver coverage and evidence: a matrix with a dated pass state per cell, re-runnable before each release. If your agency's QA line produces a Slack message saying "checkout tested", you bought a feeling. Part of the matrix can keep running after launch. Deploi's conflict-debugging record keeps each reproduced checkout failure as a synthetic checkout test that runs every 15 minutes in each region you sell ([Deploi decision record](https://deploi.ca/shopify/build-vs-buy/checkout-extension-and-theme-app-conflict-debugging), October 2026). So an app update that breaks checkout raises an alert before shoppers notice.

## When should you spend less on checkout QA?

Spend less on checkout quality assurance (QA) when the matrix is small, because the count of test cells sets the budget.

> **When a large QA allocation buys tests that do not exist**
> - **One market and one currency.** The market and currency axis of the checkout test matrix collapses to one value, so every other case runs once.
> - **Card-only payments.** Fewer payment methods shrink every combination in the checkout test matrix that multiplies by payment method.
> - **No subscriptions and no business-to-business (B2B) sales.** Both customer types drop out of the matrix, along with Shopify's B2B purchase-option and subscription limits.
> - **No two apps touch checkout.** Deploi's conflict-debugging record scores its synthetic monitor WAIT while no two apps touch the same surface ([Deploi decision record](https://deploi.ca/shopify/build-vs-buy/checkout-extension-and-theme-app-conflict-debugging), October 2026).

## Deploi's point of view

**What we've seen.** Discount stacking and tax-exempt customers are where defects concentrate, and both are combinations rather than features, which is exactly why they survive feature-by-feature testing and reach production.

**Where we disagree.** Agencies quote QA as a share of development because buyers ask for it that way. We think that norm is the reason checkout defects ship: it budgets testing against how much was built rather than against how many states a customer can reach.

**What this page adds.** that the parent's QA line item should not be quoted as a percentage at all, the six axes that define a Plus checkout matrix, and the Shopify rules that add or remove cells in it: Scripts rebuilt as Functions, B2B purchase options, subscription order limits and Managed Markets exclusions.

## When this answer changes

- Capgemini, or another survey, publishes a checkout QA share of budget.
- Shopify lets B2B orders carry subscriptions, pre-orders or try before you buy.
- Shopify lets Managed Markets carry B2B orders or subscriptions.
- The order edits API starts supporting subscriptions, or subscriptions start working with draft orders.
- Shopify ships a native synthetic checkout monitor, or Deploi re-scores its conflict-debugging record.

## Sources

1. [Capgemini, World Quality Report 2025-26](https://www.capgemini.com/insights/research-library/world-quality-report-2025-26/), checked October 8, 2026
2. [OpenText, World Quality Report 2025: AI adoption surges in Quality Engineering, but enterprise-level scaling remains elusive](https://www.opentext.com/about/press-releases/world-quality-report-2025-ai-adoption-surges-in-quality-engineering-but-enterprise-level-scaling-remains-elusive), checked October 8, 2026
3. [Shopify developer docs, Apps and B2B](https://shopify.dev/docs/apps/build/b2b), checked October 8, 2026
4. [Shopify Help Center, Considerations and payment gateways for subscription products](https://help.shopify.com/en/manual/products/purchase-options/subscriptions/considerations), checked October 8, 2026
5. [Shopify Help Center, Shopify Scripts and the Script Editor app](https://help.shopify.com/en/manual/checkout-settings/script-editor), checked October 8, 2026
6. [Shopify Help Center, Requirements and considerations for using Managed Markets](https://help.shopify.com/en/manual/international/managed-markets/requirements-and-considerations), checked October 8, 2026
7. [Shopify Community, Wrong selling plan, error: Only one-time purchase is available for B2B orders](https://community.shopify.com/t/wrong-selling-plan-error-only-one-time-purchase-is-available-for-b2b-orders/387594), checked October 8, 2026
8. [Capgemini, 15 years of World Quality Report: A journey in quality engineering and testing](https://www.capgemini.com/insights/expert-perspectives/15-years-of-world-quality-report-a-journey-in-quality-engineering-and-testing/), checked October 8, 2026
9. [Deploi Build vs. Buy, Build or Buy Checkout Extension and Theme App Conflict Debugging?](https://deploi.ca/shopify/build-vs-buy/checkout-extension-and-theme-app-conflict-debugging), checked October 8, 2026, Deploi research