Software

How to Write a Software Requirements Document — Free Template

Most software requirements documents fail by being too technical or too vague. Learn how to write one that works, with a free template you can use for your next project.

What a requirements document should achieve

A software requirements document exists to answer one question: what are we building and why? It is not a technical specification — that comes later. It is a communication tool that aligns stakeholders, developers and designers on the scope, constraints and success criteria of the project.

A good requirements document prevents the most expensive mistake in software development: building the right thing the wrong way, or worse, building the wrong thing perfectly. It sets clear boundaries so that everyone involved knows when the project is done and what counts as done.

The document should be understandable by a non-technical stakeholder and precise enough for a developer to estimate effort. Balancing those two demands is the skill.

User story format — and why it works

User stories are the building blocks of a good requirements document. They follow a simple format: As a [type of user], I want [an action] so that [a benefit].

This format forces clarity on three dimensions: who needs the feature, what they need to do, and why it matters. If you cannot articulate the benefit, you probably do not need the feature.

Example for a Bahrain business: As a sales manager, I want to receive an email notification when a lead submits a contact form so that I can follow up within one hour. This is specific, testable and clearly valuable.

Organise user stories by feature area and priority. Use the MoSCoW method: Must have, Should have, Could have, Will not have. This helps the development team make trade-off decisions when the timeline gets tight.

Functional vs non-functional requirements

Functional requirements describe what the system should do. Non-functional requirements describe how the system should behave. Both are essential, but they are written differently and tested differently.

Functional requirements	Non-functional requirements
'Users can register with an email and password'	'The registration process completes in under 2 seconds'
'The system sends a confirmation email after registration'	'99.5% of confirmation emails arrive within 5 minutes'
'Admins can export reports as CSV'	'The system supports 50 concurrent admin users'
'The system accepts Benefit Pay payments'	'Payment pages load in under 1.5 seconds on mobile'
'Users can reset their password'	'The database is backed up every 4 hours with point-in-time recovery'

Non-functional requirements are often the ones that get cut when budgets tighten, but they are the ones that determine whether users actually enjoy using the software. A system that works but is slow will fail.

Writing acceptance criteria

Acceptance criteria define the conditions a feature must meet to be considered complete. They turn a user story from a wish into a contract. Write them as a checklist that a tester can verify independently.

Use the Given-When-Then format: Given the user is on the checkout page, when they select Benefit Pay, then the payment form displays in Arabic. This format leaves no room for interpretation.

Good acceptance criteria are specific, measurable, testable and unambiguous. 'The form works well' is not acceptance criteria. 'The form shows a success message within 3 seconds of submission' is.

Template sections

A practical requirements document has six sections. Keeping it to six prevents bloat while covering what matters.

Project overview: one paragraph describing the project, the problem it solves, and who it is for.
User personas: a short profile for each user type — their goals, skill level, and how they will use the system.
Feature list with priorities: organised by user story with Must/Should/Could labelling.
Non-functional requirements: performance, security, availability, and compliance requirements (e.g. PCI DSS for payment handling).
Acceptance criteria per feature: the Given-When-Then statements that define done for each story.
Out of scope: explicitly list what is not included. This prevents scope creep better than any other single technique.

Common pitfalls and how to avoid them

The most common pitfall is mixing requirements with implementation details. 'The system will use React for the front end and Node.js for the back end' is an implementation decision, not a requirement. The requirement is 'The system runs in a web browser and supports 50 concurrent users.' Leave the technology choices to the technical team.

The second pitfall is requirements that are too vague. 'The system should be user-friendly' tells nobody anything. Instead write 'A first-time user can complete the registration process without assistance in under 3 minutes.'

The third pitfall is treating the requirements document as a one-time exercise. Requirements change as you learn more. Build a review cadence into the project plan — monthly for long projects, bi-weekly for short ones.

Learn more about our software development services. Read why software projects fail — often because of requirements problems. And see our software development timeline guide for realistic project scheduling.

Questions

Frequently asked questions

What is the difference between a software requirements document and a technical specification?

The requirements document defines what the system should do and why. The technical specification defines how the development team will build it — architecture, database design, APIs, technology choices. The requirements document comes first, the technical spec follows.

How long should a software requirements document be?

Aim for 8–15 pages for a typical business application. Longer documents rarely get read. If you need more detail, link out to supporting documents rather than bloating the main document. Shorter documents with clear priorities are more useful than comprehensive ones that nobody reads.

Who should write the requirements document?

A business analyst or product manager typically leads the writing, but the document should be reviewed by stakeholders (the people paying for the software), users (the people who will use it), and the development team (the people who will build it). All three perspectives are needed.

How do I handle changing requirements during development?

Build a change management process into the project. Small changes within a sprint can be accommodated. Larger changes should go through a formal review: assess the impact on timeline and budget, then decide whether to include them or move them to a future phase.

Do I need a requirements document for a simple website?

For a simple 5-page brochure site, a requirements document is overkill. A short brief with the pages, content requirements, and design preferences is enough. Use a requirements document for custom software, e-commerce platforms, web applications, or any project where the scope is complex.

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