User Acceptance Testing (UAT)
The final phase of software testing where real users or stakeholders verify that a system meets their business requirements and is ready for production deployment.
User Acceptance Testing is the last line of defense before software reaches end users. Unlike earlier testing phases that focus on technical correctness, UAT validates that the product actually solves the business problem it was built for. It is typically performed by product owners, business analysts, or actual end users rather than developers or QA engineers.
UAT scenarios are derived from acceptance criteria and real-world workflows. Common UAT approaches include alpha testing (internal users in a controlled environment), beta testing (external users in a real environment), and contract acceptance testing (verifying deliverables against contractual obligations).
Why It Matters for QA Teams
UAT catches misunderstandings between what was requested and what was built before they reach production, saving costly post-release fixes and protecting user trust.
Example
Before launching a redesigned checkout flow, the e-commerce team invites five customer service representatives to complete purchases using realistic scenarios. They discover that the new 'Apply Coupon' button is hidden below the fold on tablet devices, a usability issue that automated tests never flagged.