What to Include in Your Project Requirements
Requirements documents are unsexy. Nobody gets excited about writing specs. But I've seen projects fail because requirements were unclear, and I've seen projects sail smoothly because founders took the time to document what they wanted.
Whether you're working with an agency, freelancers, or your own team, good requirements make everything easier. Here's what to include.
Why Requirements Matter
Clear requirements do several things:
- They get everyone on the same page about what you're building
- They prevent expensive misunderstandings mid-project
- They give developers what they need to estimate accurately
- They provide a reference point when questions come up
- They help you think through your product before building starts
Time spent on requirements pays back 10x during development.
What to Include
Project Overview
Start with the big picture. One or two paragraphs that explain:
- What is this? A mobile app, web platform, API, internal tool?
- Who is it for? Your target users, briefly described.
- What problem does it solve? The core value proposition.
- What does success look like? How you'll know if the project succeeded.
This context helps developers understand not just what to build, but why. That understanding leads to better decisions.
User Types and Roles
List out all the different types of users and what they can do. For example:
- Guest: Can browse public content, create an account
- Registered User: Can create content, save favorites, manage profile
- Admin: Can manage users, moderate content, view analytics
Define these clearly. Role confusion causes security bugs and awkward UX.
Features and User Stories
The meat of your requirements. For each feature, describe:
- What it does: The capability you're adding
- Why it matters: The problem it solves or value it provides
- How it works: The basic flow or behavior
- Acceptance criteria: How you'll know it's done correctly
User stories are a useful format: "As a [user type], I want to [do something] so that [benefit]."
Example: "As a registered user, I want to save recipes to my favorites so that I can quickly find them later."
Then add details: clicking the heart icon saves to favorites, favorites appear on the user's profile page, removing a favorite requires confirmation, etc.
User Flows
For complex processes, document the step-by-step flow. What does the user see first? What do they click? What happens next? Where can they go from there?
Flowcharts or numbered lists work well here. The goal is to show the complete journey, not just individual screens.
Wireframes or Mockups
Pictures are worth thousands of words in requirements. Even rough sketches help developers understand what you're imagining.
You don't need pixel-perfect designs. Hand-drawn wireframes, Balsamiq mockups, or Figma sketches all work. The goal is visual communication, not final design.
Data Requirements
What information does your system need to store and manage?
For example, a user might have: email, password, display name, profile photo, account creation date, subscription status, preferences.
Think through all your objects (users, products, orders, messages, etc.) and what data each one needs. This directly shapes the database design.
Third-Party Integrations
List any external services your product needs to connect with:
- Payment processing (Stripe, PayPal)
- Authentication (Google login, Apple sign-in)
- Email (SendGrid, Mailchimp)
- Analytics (Google Analytics, Mixpanel)
- APIs (maps, weather, data providers)
Note which are required vs. nice-to-have. Each integration adds development time.
Technical Requirements
If you have technical constraints or preferences, state them:
- Required tech stack (React, Node, Python, etc.)
- Hosting requirements (AWS, Vercel, specific region)
- Performance requirements (page load time, API response time)
- Security requirements (encryption, compliance, authentication)
- Browser/device support (which browsers, iOS/Android versions)
If you don't have preferences, say so. Let the development team recommend.
Non-Functional Requirements
Beyond features, think about:
- Performance: How fast does it need to be?
- Scale: How many users should it support?
- Availability: What uptime do you need?
- Security: What data protection is required?
- Accessibility: WCAG compliance levels?
These "non-functional" requirements often determine architecture decisions.
Out of Scope
Almost as important as what's in scope: what's explicitly not included.
If you're building a web app and not a mobile app, say so. If v1 doesn't include user-to-user messaging, say so. Clear boundaries prevent scope creep.
Timeline and Priorities
Include your target dates and what's most important:
- When do you need this by?
- What's the most critical feature?
- If we run out of time, what can be cut?
- Are there external deadlines (launch event, investor demo)?
Priorities help teams make tradeoffs when reality doesn't match the plan.
How Much Detail Is Enough?
This depends on your team and project. General guidelines:
- Complex features need more detail than simple ones
- External teams need more detail than internal teams
- Novel functionality needs more detail than standard patterns
- If there's ambiguity, add clarity
A good test: could a developer who's never met you understand what to build from this document alone?
Living Document
Requirements aren't carved in stone. They evolve as you learn more.
But changes should be deliberate. Track what changed and why. Make sure everyone knows when requirements update. Don't change requirements informally through side conversations.
Common Mistakes
Too vague: "Users should be able to message each other" is vague. Real-time or asynchronous? Group chats or just 1:1? File attachments? Read receipts?
Too specific about implementation: "Use a MySQL database with an indexed VARCHAR(255) column" is too specific. Focus on what, not how. Let developers decide implementation.
Assuming context: You understand your business. Developers don't. Explain acronyms, industry terms, and business logic.
No acceptance criteria: "Add search" doesn't tell developers when they're done. "Users can search by title, filter by category, and sort by date or relevance" is testable.
Forgetting edge cases: What happens with no results? What if there's an error? What if users enter weird data?
Templates and Tools
You don't need special software for requirements. A Google Doc or Notion page works fine for most projects.
That said, some tools help:
- Figma: For wireframes and design specs
- Notion: For organizing requirements with databases
- Linear/Jira: For turning requirements into trackable tasks
- Loom: For video walkthroughs of complex flows
Pick tools your team will actually use. A simple doc that's maintained beats a complex system that's ignored.
Start Simple, Add Detail
You don't have to write perfect requirements upfront. Start with a rough document covering the basics. Share it with your development team. Their questions will reveal what needs more detail.
Requirements should be detailed enough to build from and flexible enough to evolve with your learning. Finding that balance is a skill that gets easier with practice.