App Contract Checklist Before You Sign

A practical checklist for app development contracts: scope, acceptance criteria, milestone payments, change requests, code ownership, post-launch support, and an exit plan. The goal is clarity and control before the build begins.

App Development Contract Checklist: What to Verify Before Signing

If there's one sentence that determines the future of your app project, it's this: "The contract is the written version of reality."

Even great ideas, designs, and teams won't help you if they're not properly documented on paper. Most projects that become "more expensive than expected" or "longer than promised" don't have a technical problem – their problem is that from day one, it wasn't clear exactly what would be delivered, when, at what quality, and with what mechanism for changes.

If you're still in the decision-making phase, you should first review the app ordering roadmap to know what questions to ask and what outputs to expect:

https://www.olymaris.com/blog/ordering-an-app-a-professional-roadmap-for-clients

And if you're still unsure whether you want a Native, Hybrid, or Web App, this choice also has a direct impact on the contract (time, cost, testing, store, release):

https://www.olymaris.com/blog/native-hybrid-or-web-app-which-one-is-right

This article was written so you can clarify the clauses that usually cause problems later, right from the start, before you spend even a single euro. The result is an "enforceable" contract, not a file full of nice sentences.

Part 1: Three Common Mistakes That Ruin the Contract from Day One

Mistake 1: Contract Without Precise Scope Definition

When the scope of work is vague, every new request can be considered "part of the project." This is where time and money burn. If you want to see the risks more precisely, definitely read this article:

https://www.olymaris.com/blog/10-common-app-project-risks-that-burn-time-and-budget

Mistake 2: Timeline Out of Thin Air

"Done in three months" when it becomes a contract must be written with precise assumptions: number of pages/screens, role complexity, admin panel, online payment, chat, notifications, multi-language, etc. For a realistic timeline:

https://www.olymaris.com/blog/how-long-does-it-take-to-build-a-website-or-app-a-realistic-timeline

Mistake 3: Payment Without Measurable Delivery

If payments aren't tied to measurable deliverables, conflict is inevitable: the client says "it's not ready yet," the contractor says "according to work done, payment must be made." Delivery and acceptance criteria must be clear from the start.

Part 2: Checklist of Critical Contract Clauses (What Must Be Locked Down)

Definition of Parties, Roles, and Official Communication Channel

Who exactly are the contract parties? Company/individual, registration number, address, responsible representative.
One person from the client side should be the "Product Owner" or final decision-maker.
One person from the execution team should be the "Project Manager" or technical responsible.
The official communication channel should be specified (e.g., email + a project management tool). Scattered WhatsApp messages won't be evidence later.

Project Goal and Final Outcome, Not Just Features

Instead of just writing a feature list, also define the outcome goal:

What type of user is the app for?
What is the main user journey?
What is the initial success criterion? (e.g., registration, order, booking, payment)

This ensures that during mid-project decisions, "the main story" isn't forgotten.

Scope / Precise Work Scope (With Attached Documents)

Here, attachments should be decisive:

PRD or SOW: Requirements document (even simple and light)
Wireframe or designed UI
List of roles and access levels
Platforms: iOS, Android, Web Admin, etc.
Languages and countries
Additional services: payment, SMS, email, map, analytics, chat, CRM, etc.

If you're estimating costs, I also recommend this pricing guide to understand how each part affects the price:

https://www.olymaris.com/blog/how-much-does-it-cost-to-build-an-app-a-pricing-guide-for-small-and-medium-businesses

Important Note:

Also write down "items outside the Scope." Many conflicts arise because the client assumes "this is obvious," but the execution team considers it outside the contract. Example: content creation, data entry, license purchases, server costs, ASO, advertising, photography, etc.

Definition of Delivery and Acceptance Criteria (Definition of Done + Acceptance Criteria)

This section should be like a checklist:

What conditions must each feature meet to be considered "delivered"?
On which devices/versions will testing be performed?
What should the minimum performance be?
What does basic security include? (e.g., communication encryption, password policy, logging sensitive events)
What are acceptable errors?

Professional Suggestion:

Set a formal UAT (User Acceptance Testing by the client) phase. For example: "After delivery of each milestone, the client has 7 business days to test and report defects/non-acceptance, otherwise the delivery is considered accepted." This clause is good for both the client (has the right to test) and the execution team (the project doesn't get stuck in endless testing).

Realistic Timeline + Assumptions

The timeline must come with assumptions:

When does the client deliver content/access/decisions?
What is the client's response time?
If response or decision-making is delayed, the timeline shifts accordingly.

This sentence must be clear: "Delays due to lack of cooperation/timely response from the client will be added to the project timeline."

Healthy Payment Model (Milestone-Based)

Good payment means payment proportional to risk. Common and healthy pattern:

Advance payment for start and team capacity reservation
Stage payments after delivery of each milestone
Small percentage as holdback until after launch/initial stability

This model gives the client a sense of security and the execution team predictable cash flow.

Change Management (Change Request) with Clear Formula

No project proceeds without changes. The problem is when changes become free and endless. Specify in the contract:

Change requests must be in writing
The execution team announces the impact of the change on cost and time
Execution only begins after written confirmation from the client
Changes can be priced in two ways: hourly/daily or fixed per change

If you want to see the risks of changes precisely, this article helps a lot:

https://www.olymaris.com/blog/10-common-app-project-risks-that-burn-time-and-budget

Ownership and Access (IP, Repos, Accounts)

Here it must be written precisely and without emotion, as this is the most sensitive point later:

Ownership of UI/UX files (Figma and outputs)
Ownership of source code and repository handover (Git)
Publishing accounts (Apple Developer / Google Play / Firebase / ...)
Access and access levels

Common and logical model that reduces conflicts:

"Ownership of source code and complete transfer of access is done after full settlement and payment of contract amounts." This is both commercially defensible (no seller transfers complete ownership before full settlement) and transparent for the client.

Use of Ready-Made Components and Licenses

If the project uses libraries, templates, or licensed services:

Which party bears the license costs?
In whose name is the license registered?
If the license is not renewed, which part of the app stops working?

Transparency here prevents later claims.

Warranty and Bug Fixing

Don't confuse two things: "bug" and "change request."

Bug means: something that should work according to the contract but doesn't
Change means: adding/removing or changing behavior from the initial agreement

Write in the contract:

How long is the bug-fixing warranty period after final delivery? (e.g., 30 to 60 days)
With what priority and in what SLA are bugs fixed?
Changes and new developments are outside the warranty and are estimated separately

Post-Launch Support (Support & Maintenance)

Many only see the construction costs, not the costs after launch. This section should be transparent:

Monitoring crashes and errors
Updates for new iOS/Android versions
Backup and server maintenance
Security and patches
Small improvements

You can define two plans: Basic and Pro, with specified hours per month.

Performance, Security, and Responsibilities (Responsibility Boundaries)

This section must be realistic:

100% security doesn't exist, but basic standards must be followed
Responsibility for events outside the execution team's control must be clear (e.g., third-party service outages, API sanctions, sudden changes in store rules)
If the client has payment delays, does the execution team have the right to stop work? (This clause must be clear so the project doesn't remain in a gray area)

Limitation of Liability and Damages

This clause is usually important for both parties so the project doesn't turn into a legal crisis:

Cap on financial liability of parties
That indirect damages (such as lost potential profit) usually cannot be claimed

If this clause is written correctly, it controls risk and keeps decision-making more rational.

Exit Plan or Safe Handover

Even if the collaboration is excellent, the exit path must be standardized:

If the project is stopped halfway, what will be delivered?
What is the minimum documentation?
How is the code and deployment status handed over?
How are accesses transferred?

Having an exit plan ensures no party feels held hostage and the cooperation space remains healthy.

Documentation and Training

For applications, small but real documentation is necessary:

Admin panel guide
Version release guide
Explanation of general architecture and services
List of third-party services and keys (without security disclosure in public text)

Part 3: 12 Warning Signs (Red Flags) Before Signing

These are things you should pause on if you see them in negotiations:

❌ Contract without scope attachment (just a few pages of general text)

❌ Promise of very short time without requirements review

❌ Full payment before any delivery

❌ No change request mechanism

❌ No definition of UAT and acceptance criteria

❌ Unclear code and account ownership

❌ No post-launch support plan

❌ Insistence on quick start without PRD or at least wireframe

❌ Promise of "everything is included" without precise definition

❌ No project manager/responsible person

❌ Ignoring risks and testing

❌ No transparency about third-party costs (server, SMS, map, licenses)

If you're still in the idea validation phase, this checklist helps understand whether it's worth building at all:

https://www.olymaris.com/blog/10-signs-your-app-idea-is-worth-building-full-checklist

And if you're undecided between choosing the app type and development path, keep this article handy as it has a direct impact on the contract:

https://www.olymaris.com/blog/native-hybrid-or-web-app-which-one-is-right

Part 4: A Simple Pattern for Scope Attachment (To Make the Contract "Enforceable")

If you want your contract to be practical and defensible, even a one-page attachment is enough, provided it's precise:

• List of roles: Admin / Customer / Staff / ...
• List of pages/screens (e.g., 20 screens)
• Main flows: Registration, login, payment, order, notifications
• Integrations: Payment, SMS, Maps, Analytics
• Platforms: Android + iOS + Admin Panel
• Languages: English/German (if needed)
• Outside of Scope: Content creation, advertising, ASO, service costs, data entry, etc.

This attachment transforms the contract from a general text into a project control tool.

Summary

A good contract isn't meant to make the relationship difficult; it's meant to make the relationship transparent.

When scope, delivery criteria, changes, payment, ownership, and support are clear from day one, the project moves faster, conflicts decrease, and both parties understand "how they win."

If you'd like to review the contract and scope attachment once from a technical and practical perspective before signing (without legal complication), you can start with this roadmap and proceed step by step:

https://www.olymaris.com/blog/ordering-an-app-a-professional-roadmap-for-clients

Frequently Asked Questions (FAQ)

Question 1: What is the best payment model for an app development contract?

Stage payment based on milestones and measurable delivery, along with a small holdback percentage until after launch, is usually the safest model.

Question 2: How is source code ownership determined in an app development contract?

The most common model is that the client receives ownership and full access to the code repository and accounts after full settlement.

Question 3: What is the difference between a bug and a change request?

Bug means: something that should work according to the agreement and doesn't; Change Request means: changing or adding something outside the initial agreement that must be estimated separately.

Question 4: What role does UAT or User Acceptance Testing play in the contract?

UAT is a formal period for client testing to confirm delivery of each phase or record defects; the absence of UAT leads to prolonged conflicts.

Question 5: What exactly should the contract specify as scope?

Roles, pages/screens, main user flows, additional services, platforms, languages, and items outside the scope must be clear.

Question 6: What happens if the client responds or makes decisions late?

The contract should state that delays due to lack of client cooperation will be added to the project timeline.

Question 7: How long is the bug-fixing warranty period typically after final delivery?

Depending on the project, it's common to consider 30 to 60 days for fixing bugs related to the agreed scope.

Question 8: Who bears the costs for third-party services like server, SMS, or maps?

This must be clearly specified in the contract; typically, the costs for third-party services and licenses are borne by the client unless otherwise agreed.

Question 9: What does an exit plan mean in an app development contract?

It means that if the collaboration stops, it's clear what will be delivered: code, documentation, access, and deployment status, so the project doesn't fail.

Question 10: How do we know if the proposed timeline is realistic?

The timeline must come with assumptions (number of pages, roles, integrations, testing, and client response). Promises without assumptions are not trustworthy.

App Development Contract Checklist: What to Lock Down Before You Sign