SaaS MVP scope and cost: what to build first
A first SaaS version needs only what lets one type of customer sign up, do the one job your product promises and pay for it. Everything else, such as team roles, reports and integrations, can wait. Scope is the biggest lever on cost, so decide it before you ask for quotes.
Last updated:
SaaS means software that people use in the browser and pay for on a subscription. Many founders start with a long feature list because every item feels important. The cost of a first version grows with each one, and so does the time before you learn anything from real users.
The core loop comes first
Write your product as one sentence: a [type of user] can [do one valuable thing] without [the old pain]. Anything that does not serve that sentence is a candidate for later. This is the heart of an MVP. If the term is new, start with what is an MVP.
Must have, should have, can wait
| Topic | Must have now | Often later |
|---|---|---|
| Accounts | Sign up, login, password reset | Single sign-on, team invitations, fine-grained roles |
| Core feature | The one job the product does | Secondary workflows and power-user options |
| Billing | One plan, one way to pay | Several plans, coupons, usage-based pricing, invoices |
| Data | Safe storage with access rules per user | Exports, advanced search, audit history |
| Admin | A simple way for you to see and fix data | Full back office with reports |
| Emails | Confirmation and password reset | Newsletters, drip campaigns, in-app notifications |
| Integrations | Only the one your core loop depends on | Everything customers ask for later |
| Design | Clean, clear and consistent | Custom animation, themes, white-label options |
Accounts
- Must have now
- Sign up, login, password reset
- Often later
- Single sign-on, team invitations, fine-grained roles
Core feature
- Must have now
- The one job the product does
- Often later
- Secondary workflows and power-user options
Billing
- Must have now
- One plan, one way to pay
- Often later
- Several plans, coupons, usage-based pricing, invoices
Data
- Must have now
- Safe storage with access rules per user
- Often later
- Exports, advanced search, audit history
Admin
- Must have now
- A simple way for you to see and fix data
- Often later
- Full back office with reports
Emails
- Must have now
- Confirmation and password reset
- Often later
- Newsletters, drip campaigns, in-app notifications
Integrations
- Must have now
- Only the one your core loop depends on
- Often later
- Everything customers ask for later
Design
- Must have now
- Clean, clear and consistent
- Often later
- Custom animation, themes, white-label options
Your own product may move items between columns. The point is to decide on purpose.
What makes SaaS scope grow quietly
- Multiple user roles. Each role means extra screens, rules and tests.
- Teams and organizations. Letting several people share one account changes how data is stored and protected.
- Subscription billing details. Upgrades, downgrades, failed payments and taxes are each small projects.
- Mobile apps. Adding a phone app doubles many decisions. If you need both, see SaaS plus mobile app.
- Security and privacy. Customer data needs Row Level Security or an equivalent access design from the start. Adding it late is harder.
How scope turns into cost
Cost is effort multiplied by the developer's rate, plus the extras that come with hosting and services. Cutting scope reduces effort directly. We do not quote prices here because the real number depends on your choices. How much does it cost to build an app explains the drivers in detail and how to collect comparable proposals.
A practical method is to price the product in layers. Ask for a quote for the core loop alone, then for each extra as its own line. You then see exactly what every addition costs and can decide with facts.
An example: a booking tool for dog walkers
Imagine a founder who wants a SaaS for independent dog walkers. The long list has client profiles, a calendar, group walks, route maps, invoices, reviews, a mobile app and a referral program. The core sentence is: a dog walker can let clients book a slot without any messages back and forth.
- Version one: sign up, a weekly availability setting, a booking page clients can open without an account, an email to confirm each booking and one subscription plan for the walker.
- Later, once walkers ask for it: invoices, group walks, reviews and the phone app.
- Never in version one: the referral program and route maps, which solve problems nobody has proven yet.
This is an invented example to show the method. The right split for your product comes from talking to your first users.
Running costs after launch
A SaaS has monthly costs from the first user. Two common services state their starting prices on their own pages, checked on 6 November 2026: Supabase lists a Free plan at $0 per month and a Pro plan from $25 per month with a spend cap that is on by default, and Vercel lists a Hobby plan at $0 per month for personal and non commercial use and a Pro plan at $20 per month per developer seat. A real product with many users can cost more, so ask your developer to estimate it for your expected volume.
Typical mistakes
- Building billing before anyone has said they would pay.
- Adding a second user role before the first one works well.
- Copying the feature list of a large competitor.
- Leaving data access rules for the end, when they are hardest to add.
- Counting a feature as done because it works on the developer's screen. Done means a real user could do the job.
Plan the build in milestones
Split the work so that each part ends with something you can open and test, for example login first, then the core feature, then billing. Each milestone is funded before work starts and runs 1, 2, 3, 4, 6 or 8 weeks. Milestones are from 50 to 2,000 each in your project currency. Smaller milestones also make it easier to change direction after early feedback. The milestone planner and the guide on splitting a project into milestones help you set this up.
Launch with a handful of real users, watch what they do, then spend your next budget on what they actually ask for.
Frequently asked questions
What must a SaaS MVP include?
Accounts, the single core feature, a simple way to pay and safe data handling. Anything else is optional for a first release.
Link to this answerShould billing be in the first version?
If you want to test whether people will pay, yes, in its simplest form. If you are only testing whether the idea is useful, you can start with a manual invoice and add billing next.
Link to this answerShould my SaaS start on web or mobile?
Web is usually the quicker start because it works on every device without app store review. Add a phone app once you see people need it.
Link to this answerCan AI tools build my first version?
They can speed up a prototype. Before you charge customers, have an experienced developer review security, payments and data handling. See finish your AI-built app.
Link to this answerHow do I estimate cost before I hire?
Write a brief, list features in priority order and ask for each extra as a separate line. The project brief tool can help you start.
Link to this answerRelated pages
- Build a SaaS with an independent developerPlan a SaaS product: accounts, subscriptions, technologies, an example milestone plan, what to write in the brief and how to pick a developer.
- What Is an MVP? A Plain Guide for FoundersAn MVP is the smallest version of a product that real users can try. Learn what it includes, what it leaves out and how to plan one.
- How Much Does It Cost to Build an App?What drives the cost of an app, SaaS, website or game, and how to turn a rough idea into a real quote you can compare and trust.
- How to Split a Project Into MilestonesSplit a software project into milestones that each deliver something you can see and approve. Rules, an example plan and a free planner tool.
- Free milestone planner for your projectTurn your project into an editable plan of milestones with lengths that fit the rules. Runs in your browser, stores nothing and estimates no prices.