How to Write a Software Requirements Document (SRS Template)

Last verified: April 2026 · Based on: IEEE 830 standard, Standish Group CHAOS Report data, and 150+ SRS documents created by JK Tech Hub for real client projects across web, mobile, and enterprise applications.

What Is an SRS Document and Why Does It Matter?

An SRS (Software Requirements Specification) is a comprehensive document that describes what a software system must do. It serves as the contract between stakeholders and developers — the single source of truth that everyone references throughout the project.

Here's why skipping an SRS is the most expensive mistake in software development:

• Without SRS: 40-60% of project failures are traced back to poor requirements gathering (Standish Group, 2025)
• With SRS: Requirements-related defects cost 10-200x more to fix after development than during the requirements phase (IBM Systems Sciences Institute)
• Budget impact: Projects with detailed SRS documents experience 30-50% fewer change requests and stay within 10% of original budget

Whether you're building a mobile app, web application, or enterprise system, an SRS document is your insurance policy against scope creep, miscommunication, and budget overruns.

SRS vs PRD vs BRD vs FRD: What's the Difference?

One of the most common questions we hear from clients at JK Tech Hub is: "Do I need an SRS, a PRD, a BRD, or something else entirely?" These acronyms are frequently confused, and many teams use them interchangeably — which leads to misaligned expectations. Here's a clear breakdown of each document, what it covers, who writes it, and when you need it.

Document	Full Name	Focus	Written By	Audience	When Created
BRD	Business Requirements Document	WHY — Business goals, problems, and success metrics. No technical details.	Business Analyst or Project Sponsor	Executives, stakeholders, investors	Before project approval
PRD	Product Requirements Document	WHAT — Features, user stories, product vision, and release roadmap from the product perspective.	Product Manager	Product team, designers, developers	After BRD approval, before design begins
SRS	Software Requirements Specification	HOW (at specification level) — Detailed functional & non-functional requirements, data models, system interfaces, acceptance criteria.	Business Analyst or Technical Lead	Developers, QA engineers, architects	After PRD, before development begins
FRD	Functional Requirements Document	WHAT the system does — Subset of SRS focusing only on functional behavior (inputs, processing, outputs).	Business Analyst	Developers, QA engineers	Can replace SRS for simpler projects

Which document do you actually need? For most projects at the small-to-medium scale (the kind JK Tech Hub handles daily from our Rajkot office), a well-written SRS that incorporates business context up front is sufficient. You do not need all four documents. Here is our practical recommendation:

• Startup MVP or small app (under 3 months): A combined PRD + SRS document is enough. We create this for clients in our discovery workshop.
• Mid-size project (3-9 months): Separate BRD (1-2 pages of business context) and a full SRS. This is what we recommend and deliver as standard.
• Enterprise or compliance-heavy project (9+ months): Full BRD, PRD, and SRS as separate documents with formal traceability between requirements.

The critical takeaway: regardless of which document names you use, the requirements must be written down, specific, measurable, and signed off before development begins. A project with no written requirements has a 65% failure rate according to the Standish Group's data — the document's name matters far less than the discipline of creating it.

SRS Template: 8 Essential Sections

Here's the complete structure of a professional SRS document. Use this as your template:

Section 1: Introduction

Sub-section	What to Include
1.1 Purpose	What this document covers, who it's for, and what software it describes
1.2 Scope	What the system will and won't do (boundaries are critical)
1.3 Definitions & Acronyms	Every domain-specific term defined so developers and stakeholders share vocabulary
1.4 References	Related documents — wireframes, business case, competitor analysis
1.5 Overview	How this document is organized

Section 2: Overall Description

Sub-section	What to Include
2.1 Product Perspective	How this system fits into the larger ecosystem (standalone, replacement, extension)
2.2 User Classes	All user types (admin, end-user, API consumer) with their characteristics and access levels
2.3 Operating Environment	Browsers, OS, devices, infrastructure (cloud, on-premise)
2.4 Constraints	Budget, timeline, technology mandates, regulatory requirements
2.5 Assumptions	What you're assuming to be true (client provides content, third-party API remains stable)

Section 3: Functional Requirements

This is the heart of your SRS. Each functional requirement should follow this format:

Field	Example
ID	FR-001
Title	User Registration
Description	The system shall allow users to register using email, phone, or Google OAuth
Input	Name, email, password (8+ chars, 1 uppercase, 1 number), phone (optional)
Processing	Validate email uniqueness, hash password with bcrypt, send verification email
Output	Success: account created + verification email sent. Failure: specific error message
Priority	Must Have (MoSCoW)
Acceptance Criteria	User can register, receives email within 60 seconds, can log in after verification

Pro tip: Use the MoSCoW method to prioritize: Must Have, Should Have, Could Have, Won't Have (this release). This prevents scope creep by making trade-offs explicit.

Real Example: Functional Requirements for an E-Commerce App

To make this concrete, here are four functional requirements exactly as they would appear in a production SRS document. These are modeled on real requirements JK Tech Hub has written for e-commerce clients in India.

Field	FR-001: User Registration
Description	The system shall allow new users to create an account using email address, mobile number with OTP, or Google OAuth 2.0.
Input	Full name (2-100 characters), email (valid format, unique), password (minimum 8 characters, at least 1 uppercase, 1 number, 1 special character), mobile number (10-digit Indian format with +91 prefix, optional).
Processing	1. Validate email uniqueness against user database. 2. Hash password using bcrypt with cost factor 12. 3. Generate 6-digit OTP for mobile verification (valid for 5 minutes, max 3 attempts). 4. Send verification email via SendGrid with 24-hour expiry link. 5. Create user record with status "pending_verification".
Output	Success: HTTP 201, account created, verification email/SMS sent, redirect to "verify your account" page. Failure: HTTP 409 (duplicate email), HTTP 422 (validation errors with field-specific messages).
Priority	Must Have
Acceptance Criteria	1. User can register via email and receives verification email within 60 seconds. 2. User can register via Google OAuth and is logged in immediately. 3. Duplicate email shows "This email is already registered" message. 4. Password not meeting criteria shows real-time validation feedback.

Field	FR-002: Add to Cart
Description	The system shall allow authenticated and guest users to add products to a shopping cart with quantity selection and variant choice (size, color).
Input	Product ID, selected variant (SKU), quantity (1-10 per item, configurable per product), user session ID or authenticated user ID.
Processing	1. Verify product is in stock and active. 2. Check requested quantity against available inventory in real-time. 3. If user is authenticated, persist cart to database. If guest, store in session/localStorage with 30-day expiry. 4. Recalculate cart totals (subtotal, applicable taxes, estimated shipping). 5. Reserve inventory for 30 minutes (configurable) to prevent overselling.
Output	Success: Cart updated with new item, cart badge count incremented, mini-cart flyout displays updated totals. Failure: "Only X items available" if insufficient stock; "Product unavailable" if discontinued.
Priority	Must Have
Acceptance Criteria	1. Product added to cart appears within 500ms with animation feedback. 2. Cart persists across browser sessions for authenticated users. 3. Guest cart merges with authenticated cart upon login. 4. Out-of-stock products show "Notify Me" button instead of "Add to Cart".

Field	FR-003: Checkout & Payment
Description	The system shall process orders through a multi-step checkout flow supporting Razorpay (UPI, cards, net banking), Cash on Delivery, and wallet payment methods.
Input	Shipping address (with pincode validation against serviceable areas), billing address (optional, defaults to shipping), selected payment method, coupon code (optional), delivery preference (standard/express).
Processing	1. Validate all cart items are still in stock. 2. Calculate final totals: subtotal + GST (18% for most categories) + shipping (free above INR 499) - coupon discount. 3. For online payment: create Razorpay order, redirect to payment gateway, handle callback. 4. For COD: verify order value is under INR 5,000 and pincode is COD-eligible. 5. On payment success: generate order ID (format: ORD-YYYYMMDD-XXXX), decrement inventory, send order confirmation email and SMS, trigger warehouse notification.
Output	Success: Order confirmation page with order ID, estimated delivery date, and payment receipt. Email confirmation within 2 minutes. Failure: Payment failed page with retry option (order held for 30 minutes). Inventory restoration if payment not completed within timeout.
Priority	Must Have
Acceptance Criteria	1. Complete checkout flow takes under 3 minutes for returning users. 2. Razorpay payment processes within 15 seconds. 3. Order confirmation email received within 2 minutes. 4. Failed payment does not create a confirmed order. 5. Coupon validation happens server-side, not just client-side.

Field	FR-004: Order Tracking
Description	The system shall allow users to track order status in real-time through a visual timeline showing all stages from confirmation to delivery.
Input	Order ID or user account (shows all orders), optional: AWB (Air Waybill) number for direct courier tracking.
Processing	1. Fetch order status from internal database. 2. For shipped orders, poll courier partner API (Shiprocket/Delhivery) every 2 hours for tracking updates. 3. Map courier statuses to internal statuses: Order Placed, Processing, Packed, Shipped, Out for Delivery, Delivered. 4. Trigger push notification and SMS on each status change. 5. Calculate and display estimated delivery date based on courier SLA and destination pincode.
Output	Visual timeline with timestamps for each completed stage, current stage highlighted. Map view showing package location for shipped orders. Estimated delivery date with confidence indicator. "Contact Support" button for delayed orders (beyond estimated date + 2 days).
Priority	Must Have
Acceptance Criteria	1. Order status page loads within 2 seconds. 2. Tracking updates reflect courier status within 2 hours. 3. Users receive push notification within 5 minutes of status change. 4. Guest users can track orders via order ID + email/phone combination. 5. Delivered orders show "Rate & Review" prompt.

Notice how each requirement is specific, measurable, and testable. A developer reading FR-003 knows exactly what payment methods to integrate, what the GST calculation logic is, and what the order ID format should be. A QA engineer can write test cases directly from the acceptance criteria. This level of detail is what separates a useful SRS from a vague wishlist.

Section 4: Non-Functional Requirements

Category	Example Requirement
Performance	Page load time under 2 seconds for 95% of requests; support 1,000 concurrent users
Security	OWASP Top 10 compliance; data encrypted at rest (AES-256) and in transit (TLS 1.3)
Scalability	Horizontal scaling to 10x current load within 30 minutes
Availability	99.9% uptime (8.7 hours max downtime per year)
Usability	New users complete core task within 3 minutes without training
Accessibility	WCAG 2.1 AA compliance for all public-facing pages
Maintainability	80%+ code coverage; modular architecture with documented APIs

NFR Examples by Project Type

Non-functional requirements vary significantly based on what you are building. Here are realistic NFR benchmarks drawn from JK Tech Hub's project archives across different verticals:

NFR Category	E-Commerce App	Healthcare Portal	FinTech / Banking App	Internal ERP System
Performance	Product page loads in under 1.5s; search results in under 800ms; checkout completes in under 3 steps	Patient records load in under 2s; appointment booking confirms within 5s	Transaction processing under 500ms; real-time balance updates within 2s	Dashboard loads in under 3s; report generation under 30s for up to 100K records
Security	PCI DSS compliance for payment data; SSL/TLS for all pages; session timeout after 30 minutes of inactivity	HIPAA/ABDM compliance; end-to-end encryption for patient data; audit trail for all record access; role-based access with MFA	RBI data localization compliance; AES-256 encryption at rest; multi-factor authentication mandatory; transaction signing	LDAP/Active Directory integration; IP whitelisting; session management with auto-logout after 15 minutes
Availability	99.9% uptime (8.7 hours max downtime/year); 99.99% during sale events	99.95% uptime; emergency access available even during maintenance windows	99.99% uptime (52 minutes max downtime/year); zero-downtime deployments mandatory	99.5% uptime during business hours (Mon-Sat 9am-8pm IST); planned maintenance on Sundays
Scalability	Handle 10x normal traffic during flash sales; auto-scale from 100 to 10,000 concurrent users within 5 minutes	Scale to 500 concurrent users; handle bulk appointment booking during vaccination drives	Support 50,000 concurrent users; handle 1,000 transactions per second during peak hours	Support 200 concurrent users across 5 office locations; handle month-end reporting loads
Data Retention	Order history: 7 years; user analytics: 2 years; deleted accounts: anonymize after 90 days per GDPR/DPDPA	Patient records: indefinite retention; audit logs: 10 years minimum; comply with DISHA Act requirements	Transaction records: 10 years per RBI regulation; KYC documents: 5 years post account closure	Financial records: 8 years per Companies Act; employee data: 5 years post-exit per labor law

The key lesson here: NFRs are not generic boilerplate you copy from a template. They must be tailored to your industry's compliance requirements, your users' expectations, and your infrastructure budget. A healthcare app that meets only e-commerce-grade security is a compliance violation waiting to happen.

Section 5: System Architecture

Include high-level architecture diagrams showing frontend, backend, database, third-party integrations, and deployment infrastructure. Use tools like draw.io, Excalidraw, or Lucidchart.

Section 6: Data Requirements

Define the data model — entities, relationships, data types, validation rules, and retention policies. Include an ER diagram for complex systems.

Section 7: External Interfaces

Document every integration: payment gateways, email services, third-party APIs, hardware interfaces. For each, specify: endpoint, authentication method, data format, rate limits, and fallback behavior.

Section 8: Appendix

Wireframes, mockups, user flow diagrams, glossary, revision history, and sign-off page.

SRS vs PRD vs BRD vs FRD: What's the Difference?

These documents are often confused. Here's the definitive breakdown:

Document	Written By	Audience	Focus	When Created
BRD (Business Requirements)	Business Analyst / Product Manager	Stakeholders, executives	WHAT the business needs (goals, problems)	Before project approval
PRD (Product Requirements)	Product Manager	Design + engineering teams	WHAT the product should do (features, user stories)	After BRD approval
SRS (Software Requirements)	Business Analyst / Tech Lead	Development + QA teams	HOW the software fulfills requirements (detailed specs)	After PRD, before development
FRD (Functional Requirements)	Business Analyst	Development team	Detailed functional behavior (subset of SRS)	Part of SRS

For most Indian SMB projects: You don't need all four documents. A combined SRS that includes business context (from BRD), feature descriptions (from PRD), and technical specifications works perfectly. Save the multi-document approach for enterprise projects with 50+ stakeholders. At JK Tech Hub, we create a single comprehensive SRS that covers all four aspects.

Complete Functional Requirements Example: E-Commerce App

Here's what properly written functional requirements look like for a real project — an e-commerce mobile app:

ID	Title	Description	Priority
FR-001	User Registration	System shall allow registration via email, phone (OTP), or Google OAuth. Email requires verification within 24 hours. Phone requires OTP verification. Password: minimum 8 characters, 1 uppercase, 1 number.	Must Have
FR-002	Product Search	System shall support text search with auto-suggestions (response time <200ms), filters (price range, category, brand, rating), and sorting (price low-high, newest, popularity). Results paginated at 20 items/page.	Must Have
FR-003	Add to Cart	User can add products with quantity selection (max 10 per item). Cart persists across sessions for logged-in users. Guest cart persists for 7 days via local storage. Cart shows real-time price with GST breakdown.	Must Have
FR-004	Checkout & Payment	Support: Razorpay (UPI, cards, net banking, wallets), COD (for orders under ₹5,000). Address: saved addresses + new address with PIN code auto-fill. GST invoice generated automatically. Order confirmation via email + SMS + WhatsApp.	Must Have
FR-005	Order Tracking	Real-time order status: Confirmed → Packed → Shipped → Out for Delivery → Delivered. Push notification at each stage. Delivery partner tracking integration (Shiprocket API). Estimated delivery date shown at checkout.	Should Have

Notice the specificity: Each requirement defines exact behavior, input validation rules, error handling, and acceptance criteria. "The app should have a shopping cart" is NOT a requirement — it's a wish. FR-003 above is a requirement because a developer can build it and a tester can verify it without asking questions.

What Happens When You Skip the SRS?

We've rebuilt 15+ projects at JK Tech Hub that originally failed because they started coding without an SRS. Here's what typically goes wrong:

• 2-3x budget overrun: Without defined scope, "just one more feature" requests accumulate. A ₹5 lakh project becomes ₹12 lakh. Every change requires rework because the architecture wasn't designed for it.
• 3-6 month delay: Developers build the wrong thing, then rebuild. Stakeholders disagree about what was promised. Arguments replace progress. The original 3-month timeline becomes 9 months.
• Broken relationships: "I said X, you built Y" disputes destroy client-agency trust. An SRS with sign-off eliminates he-said-she-said by documenting exactly what was agreed.
• Untestable software: Without acceptance criteria, QA doesn't know what to test. Bugs ship to production. Users find the bugs. Your reputation suffers.

The cost of writing an SRS (1-2 weeks, ₹50,000-₹2 lakh for a professional BA) is 5-10% of your project budget. Skipping it risks 50-200% cost overrun. The math is obvious.

Real SRS Examples by Project Type

Project Type	SRS Length	Key Focus Areas
Mobile App (MVP)	8-15 pages	User stories, API specifications, push notification logic, offline behavior
E-Commerce Platform	20-40 pages	Product catalog schema, payment flows, inventory rules, shipping calculations
ERP System	50-100+ pages	Module specifications, role-based access matrix, data migration plan, reporting
SaaS Product	25-50 pages	Multi-tenant architecture, subscription billing logic, API documentation

Common SRS Mistakes (and How to Fix Them)

1. Too vague: "The system should be fast" → Fix: "API response time under 200ms for 95th percentile under 500 concurrent users"
2. Too technical: Writing implementation details instead of requirements. The SRS should say WHAT, not HOW.
3. Missing edge cases: What happens when payment fails? When the user loses internet? When data exceeds limits? Document every exception.
4. No acceptance criteria: If you can't test it, it's not a requirement. Every functional requirement needs measurable criteria.
5. Stakeholder sign-off skipped: All stakeholders must review and approve the SRS before development begins. No exceptions.
6. Never updated: The SRS is a living document. Update it when requirements change and maintain a revision log.

Tips for Writing an Effective SRS

• Use user stories alongside formal requirements: "As a [user], I want to [action] so that [benefit]" makes requirements human-readable.
• Include wireframes: A picture is worth 1,000 words of requirements. Low-fidelity wireframes prevent 80% of UI-related change requests.
• Prioritize ruthlessly: An MVP SRS should have 60% Must-Have, 20% Should-Have, and 20% Could-Have features.
• Write for two audiences: Business stakeholders and developers. Use plain English with technical appendices.
• Version control: Use Google Docs with version history or store in your Git repo alongside code.

JK Tech Hub's SRS Process

At JK Tech Hub, we include SRS creation as part of every project engagement at no extra charge. Our process:

1. Discovery Call (1-2 hours): Understand your business goals, users, and constraints
2. Requirements Workshop (2-4 hours): Map user flows, define features, prioritize with MoSCoW
3. SRS Draft (3-5 days): Our BA team creates a complete SRS with wireframes
4. Review & Sign-off: You review, we revise until approved. Typically 1-2 revision rounds.
5. Development begins only after SRS is signed off — no ambiguity, no surprises

This process has helped us maintain a 95%+ on-time delivery rate across 150+ projects. Request a free SRS consultation or get an instant project estimate.

Related Resources

• How to Hire Developers in India
• Developer Cost in India: 2026 Rates
• Web Application Development Services
• Mobile App Development Services
• Project Cost Calculator

Sources

• IEEE 830-1998 — Recommended Practice for Software Requirements Specifications
• Standish Group — CHAOS Report on Project Failures