How to Write a Product Requirements Document (PRD) for Your MVP

A PRD is a contract between product and engineering. When it's missing, you get scope creep, misaligned expectations, and features nobody asked for built at the expense of features everyone needed. For MVPs specifically, a tight PRD is the difference between shipping in 6 weeks and shipping in 6 months.

What a PRD Is (And Isn't)

A PRD defines what you're building, who it's for, what success looks like, and what's explicitly out of scope. It does NOT specify how to build it (engineering's job), every edge case (over-engineering the doc), or the final design (mockups accompany the PRD).

PRD Structure for MVPs

1. Overview (1 Paragraph)

One paragraph explaining what this product is, who it's for, and why it matters right now. If you can't write this paragraph clearly, you're not ready to write a PRD.

"Invoicely is a standalone invoicing tool for freelance designers who currently use spreadsheets and email to manage client billing. The MVP enables designers to create branded invoices, send them via email, and receive payment confirmation — reducing their average invoicing time from 45 minutes to under 5 minutes."

2. Problem Statement

The specific problem, for who, and why solving it matters. Use data from user interviews. Avoid vague statements like "the market needs a better solution." Include: the user and context, the specific friction, the current alternative, and the business/user impact.

3. Goals and Non-Goals

Explicit goals and explicit non-goals are equally important. For an MVP, the non-goals list should be longer than the goals list.

Goals (MVP)	Non-Goals (MVP)
Create and send invoices in <5 minutes	Multi-currency support
Accept Stripe payment and confirm receipt	Tax calculation
Store invoice history per client	Recurring invoices / subscriptions
	Mobile app
	Team / multi-user access
	Accounting software integrations

Non-goals are your scope firewall. When a stakeholder asks "why don't we add X?", you point to the non-goals list.

4. Users and Roles

Define who uses this product and their context. For MVPs, typically 1–2 user types with clearly differentiated permissions and interaction patterns.

5. User Stories and Acceptance Criteria

User stories define what users can do. Acceptance criteria define what "done" means. Together they form the backbone of your engineering spec.

Format: As a [user type], I want to [action] so that [outcome].

US-01: Create Invoice
As a freelance designer, I want to create a new invoice so that I can bill for completed work.

Acceptance criteria:

• User can fill: client name, email, auto-generated invoice number, due date, line items.
• User can add/remove line items. Total calculates automatically.
• User can preview before sending. Invoice can be saved as draft.

US-02: Send Invoice
As a freelance designer, I want to send the invoice via email so that my client receives a payment link.

Acceptance criteria:

• Client receives email with invoice PDF and payment link.
• Invoice status updates to "Sent" with timestamp.
• Retry option available if send fails.

US-03: Client Pays Invoice
As a client, I want to pay the invoice via credit card so that the designer receives payment.

Acceptance criteria:

• Payment link opens Stripe Checkout without requiring client login.
• Payment confirmation sent to both client and designer.
• Invoice status updates to "Paid" in designer's dashboard.

6. High-Level Data Model

Name the core entities to align engineers before they start:

• User: id, email, name, stripe_connect_id, logo_url
• Client: id, user_id, name, email, company
• Invoice: id, user_id, client_id, status, due_date, line_items, total
• Payment: id, invoice_id, stripe_payment_intent_id, amount, paid_at

7. Success Metrics

Define success before you build, not after:

• Primary: Time to first invoice sent (target: <5 minutes from signup)
• Engagement: % invoices paid within 14 days of sending
• Retention: % users who send a second invoice within 30 days
• Business: MRR at 30/60/90 days post-launch

What Makes a PRD Bad

• Too long: A 40-page PRD means decisions haven't been made. Decisions belong in the PRD; debate belongs before it.
• Missing acceptance criteria: Engineers fill ambiguity with their best guess — usually not what product intended.
• No non-goals: Without explicit out-of-scope definition, everything is in scope.
• Technical how instead of product what: PRD says "use PostgreSQL." That's engineering's decision. PRD should say what the capability must enable — how is up to the team.

For the tech stack decisions that follow PRD sign-off, see How to Choose the Right Tech Stack for Your MVP. For agile execution during the build, see How Agile Sprints Accelerate MVP Development.

FAQs

What should a product requirements document include?

A PRD should include: a one-paragraph overview, problem statement with user context, explicit goals and non-goals, user types and roles, user stories with acceptance criteria, high-level data model, technical constraints, and success metrics. For MVPs, the non-goals list should be longer than the goals list — scope discipline is the most important function of the document.

How long should a PRD be for an MVP?

For an MVP, 3–8 pages is ideal. A PRD longer than 10 pages usually means decisions haven't been made yet — scope hasn't been cut, requirements haven't been prioritized. Long PRDs generate long arguments and long development cycles. If you can't summarize it in 5 pages, cut more scope.

What is the difference between a user story and acceptance criteria?

A user story describes what the user wants to accomplish: "As a designer, I want to create an invoice." Acceptance criteria define exactly what "done" means: what fields must be fillable, what the system must do when submitted, what the user sees on completion. Acceptance criteria make user stories testable and unambiguous.

Do you need a PRD for an MVP?

Yes — especially for outsourced or agency development where the builders aren't the ones who conceived the product. Without a PRD, you'll get the product the engineering team imagined, not the one your users need. Even a 3-page lean PRD dramatically reduces misalignment, rework, and scope creep during the build.