Acceptance Testing: How to Sign Off a Delivered Project
By CodexierPublished 7 min read
The end of a website or software project is often the least defined part of it. The supplier says it is done, the buyer is not sure, invoices and go-live dates hang in the air, and the relationship sours over what counts as finished. Acceptance testing fixes that by making done a checklist agreed in advance. This guide explains how to set the criteria, run the test period, classify what you find, and sign off in a way that protects both sides.
The short answer
Every fixed-price website launch we deliver ends with this process, because a clear sign-off is as much in our interest as in yours.
Acceptance criteria agreed up front
Acceptance criteria are the requirements in a testable form. It looks like this rather than it should be modern. Each criterion should be something a person can check and answer yes or no. Write them together with the supplier during scoping and attach them to the agreement; a criterion invented at the end is an argument, not a test.
| Area | Example criterion | How it is checked |
|---|---|---|
| Content and pages | All pages in the sitemap exist with approved copy and images | Walk the sitemap; compare with the approved content |
| Functions | Contact form sends to the agreed address and shows a confirmation | Send a test message from a phone |
| Devices and browsers | Layout works on current iPhone and Android phones and the two main desktop browsers | Open each page type on each device |
| Performance | Key pages pass Core Web Vitals on mobile | Run the agreed measurement tool |
| Legal and tracking | Cookie banner, privacy pages and analytics behave as specified | Checklist in a private browser window |
| Handover | Admin access, documentation and training delivered | Confirm receipt of each item |
The acceptance test period
The supplier declares the delivery ready for acceptance, and a fixed period starts, usually one to two weeks for a website and longer for a larger system. During it, you test against the criteria on a staging address or in a test environment, with real people from your company doing the tasks they will do in production. Log every finding in a single shared list with a description, where it happens, how to reproduce it, and which criterion it relates to. Do not send findings by email as they occur; one list is the only way to know when you are finished. If no findings are reported within the period, most agreements treat the delivery as accepted, so plan the time before you agree the dates.
- Test with the people who will use the system, not only the project lead.
- Test on real devices over mobile data, and with real content, not placeholder text.
- Reproduce each finding once before logging it; a finding nobody can reproduce cannot be fixed.
- Hold a short review at the end of the period to agree the status of every item on the list.
Defects vs change requests
Everything on the list is one of three things. A defect: the delivery does not meet an agreed criterion, and the supplier fixes it within the price. A change request: it meets the criteria, but now that you see it you want something different, which is legitimate and is quoted and scheduled separately. A question: you are not sure whether something is intended, and a short conversation settles it. Most disputes at the end of a project come from treating change requests as defects, in both directions. Having the criteria in writing is what makes the classification quick rather than personal.
Critical defect
Blocks a core function: the checkout fails, the form does not send, the site is down on mobile. Must be fixed before sign-off.
Minor defect
Cosmetic or an edge case that does not block use. May be listed and fixed after sign-off by an agreed date.
Change request
New or different behaviour outside the criteria. Priced separately; never blocks sign-off of what was agreed.
Signing off and what it triggers
Sign-off is a written statement, an email suffices, that the delivery meets the acceptance criteria, optionally with a list of minor defects and the date by which they will be fixed. It normally triggers three things: the final invoice becomes due, the delivery moves to production or the launch date is confirmed, and the warranty period begins. Because it has those consequences, it should be given by someone with authority to accept, and it should not be withheld over change requests. Equally, a supplier should not demand sign-off while a critical defect is open. If the parties disagree on whether a criterion is met, the criterion's own check method decides; that is why the method is written next to each one.
Warranty after acceptance
A warranty period after sign-off covers defects that were present at delivery but discovered later: a form that fails for a particular browser, a page that breaks with real data volumes. It does not cover changes you request, problems caused by your own edits, or third-party services changing. Agree its length in the contract, typically one to three months for a website, and agree what happens after: a maintenance plan, hourly support or nothing. In Swedish business-to-business agreements there is no statutory warranty for services of this kind beyond general contract law, so what is written is what you have.
When you do not need a formal process: a small fixed-scope job such as a landing page can be accepted with a single checklist and an email. The full process pays for itself on anything with a checkout, integrations, several stakeholders or a launch date that matters. Getting the criteria into the quote in the first place is covered in our guides to what a webshop quote should include and estimates, quotes and fixed prices. If you are about to sign off a delivery and are not sure it is ready, book a call and we will go through the list with you; our own fixed-price packages, with their acceptance terms, are on the pricing page.
Frequently asked questions
What if we did not agree acceptance criteria at the start?
Write them now, together, from the original quote and any specifications, before the test period starts. It is late but far better than testing against nothing. Where the quote was vague, agree a reasonable interpretation in writing and move on; arguing about intent rarely ends well for either side.
Can we withhold payment until every defect is fixed?
Withholding the final payment over critical defects is normal and usually provided for in the agreement. Withholding it over minor defects with an agreed fix date, or over change requests, is not, and damages the relationship you will need during the warranty. Most agreements tie the final invoice to sign-off, with minor items listed.
How long should the test period be?
Long enough for the people who will use the system to try every criterion once with real content, and short enough that the project does not drift. One to two weeks for a website, two to four for a webshop or an application with integrations. Agree it in the contract along with what happens if you do not respond in time.
Who should sign off?
Someone with authority to accept the delivery and approve the invoice, informed by the people who tested. In a small company that is the owner. Name the person in the agreement so there is no doubt on the day.
About to accept a delivery and not sure it is ready?
Send us the quote and your list of findings. In fifteen minutes we help you sort defects from change requests and tell you whether sign-off is reasonable now or what should be fixed first.
Book a free 15-minute call