How Long Does It Take to Build Custom Software?

Longer than your CEO believes. Shorter than your worst nightmare. Custom software London is 2-24 months, depending on what you're making and if you can avoid adding features en route. Most will fall in the 3-12 month time frame. Enterprise giants? Those take longer than 24 months when decision-makers negotiate button colours.

Need precise estimates? Forget calendar-month thinking. Think in phases by scope. That's how timelining works when you're not fantasising about complexity. 

It Depends On What You Are Actually Creating.

There are three types of projects that rule custom development. Each has a predictable timeline if you don't ruin them with scope creep. Identify which bucket your project is in before you can ask "when will it be done?"

MVP: Can You Ship in 2-4 Months?

Minimum Viable Products are 2-4 months. Period.

This presumes that you actually mean "minimum." Not "everything except the kitchen sink because marketing wants it." MVPs fix one fundamental issue with bare-bones functionality. No dashboard analytics. No custom reporting. No integrations other than absolute necessities.

You're testing an idea, not releasing a completed product. The second you add "nice-to-haves," you're developing a complete application masquerading as an MVP.

Full Business Application: Why 6-12 Months

6-12 months is the amount of time standard business software needs to be executed correctly.

These are not toy projects. You're creating rich feature sets, smart UIs, multiple roles, and integrations with legacy systems. CRM platforms, inventory management applications, or customer portals with payment gateways come to mind.

Inflation of timelines occurs when stakeholders don't accurately estimate integration complexity. Integrating with Salesforce, SAP, or legacy databases? Each takes weeks, not days. New REST APIs integrate seamlessly. Proprietary systems from 2008? Pain ahead.

Enterprise Systems: 12-24+ Months Ready?

Sophisticated enterprise systems take a minimum of 12-24 months. ERP systems, B2B marketplaces, and multi-tenant SaaS platforms require significant requirements gathering, regulatory work, and interdepartmental integration that don't speak to each other. 

Healthcare, finance, or government deals? Put on another 6 months. Compliance documentation outweighs actual code volume.

Why so long? Bureaucracy, mostly. Technical complexity exists, but stakeholder alignment consumes more time than development itself.

Where Does the Time Actually Go?

Software development follows predictable stages. Each consumes specific durations based on project complexity. Think you can skip phases to save time? You guarantee expensive rework later.

Research and Planning: Are 4-8 Weeks Worth It?

You can't skip discovery without paying for it later.

Requirements gathering, user research, competitive analysis, and technical architecture planning all happen here. Teams define business goals, document system requirements, and establish realistic scope boundaries (which 70% of projects fail to maintain).

Inadequate planning creates chaos that you'll spend months untangling during development. Every hour spent here saves five hours of confused engineers asking "what did the client actually want?"

Design and Architecture: Why 6-10 Weeks?

Wireframes, prototypes, technical specs, the foundation before code.

UI/UX designers map user flows while architects define system structure, database schemas, and integration patterns. Complex applications with multiple user roles or intricate workflows? Push this toward 10 weeks.

Stakeholder approval adds 1-2 weeks to the revision cycles. Budget for it now or experience it as unplanned delays later.

Core Development: What Happens in 12-24 Weeks?

Where actual building happens. Where optimism dies.

Developers work in sprints (typically 2-4 weeks each), building features incrementally with continuous testing. Integration work; connecting components and third-party services; adds 3-6 weeks, depending on API quality and documentation completeness.

Agile methodology accelerates this phase by 15-30% compared to Waterfall. That is, if your team actually practices Agile instead of "chaos with standups."

Testing and Refinement: Can You Skip 4-8 Weeks?

Finding bugs before users do costs less than fixing them after launch.

User acceptance testing, performance testing, security audits; all mandatory unless you enjoy production outages and data breaches. Bug fixes consume more time than anticipated because complex systems have emergent issues that only appear under real-world conditions.

Deployment: Why 3-6 Weeks?

Production deployment, app store submissions, and final configurations.

iOS app review takes 2-3 days. Android takes 3-7 days. Enterprise deployments requiring infrastructure setup, data migration, and user training? This phase extends significantly.

What's Slowing You Down?

Theoretical timelines assume perfect conditions. Reality introduces friction at every phase. Most delays trace back to predictable causes that teams refuse to address proactively.

Is Scope Creep Killing Your Timeline?

Requirements that expand mid-project destroy timelines.

"Just one more feature" compounds into months of delay. Stakeholders who can't differentiate between essential and optional functionality guarantee budget overruns and missed deadlines.

Formal change request processes with documented impact analysis prevent this. Most teams skip this discipline, then act surprised when projects drag.

How Complex Are Your Integrations?

Every third-party integration adds risk.

Modern APIs integrate smoothly; Stripe, Twilio, and Google Maps work as documented. Legacy systems or poorly-maintained APIs require reverse engineering and workarounds that consume weeks per integration.

Most software includes 3-5 integrations even in MVP versions. Each one represents a dependency outside your control.

Does Team Size Actually Help?

More developers don't mean faster delivery.

Teams of 3-5 people achieve the best results without coordination overhead. Nine or more developers? Communication complexity explodes. Time spent in alignment meetings exceeds time spent coding.

Is Your Methodology Wrong?

Agile vs. Waterfall isn't just terminology: it's a 15-30% timeline difference.

Agile delivers working software faster through iterative cycles with continuous feedback. Changes get incorporated without massive rework. Waterfall follows rigid sequential phases, predictable but inflexible. Once you complete the design, changing it requires restarting the entire process.

Regulated industries often mandate Waterfall for compliance documentation. Everyone else choosing Waterfall is choosing slower delivery for no benefit.

How Do You Actually Speed This Up?

Strategic decisions reduce timelines without compromising quality. Are you willing to make intelligent tradeoffs instead of demanding everything instantly?

Why Rebuild What Exists?

Stop rebuilding what already exists.

Payment processing? Use Stripe or PayPal. Authentication? OAuth or Google Sign-In. Mapping? Google Maps API. Communication? Twilio. These proven solutions integrate in days, comply with industry standards, and eliminate months of development.

Can You Launch with Less?

Launch with core functionality. Add features based on real usage.

Every feature delayed to version 2.0 represents time saved now and development guided by actual user feedback instead of assumptions. Most "essential" features get used by 5% of users.

Should You Outsource Strategically?

External teams enable parallel development.

Different project components progress simultaneously instead of sequentially. Hiring external specialists provides immediate expertise without months of recruitment and training. The time savings come from avoiding the hiring process; posting jobs, interviewing, and onboarding can consume 3-6 months before productive work begins.

Did You Define Requirements Clearly?

Vague requirements guarantee delays.

Teams constantly seeking clarification lose momentum. Thoroughly documenting requirements, aligning them with business strategy, and securing stakeholder agreement before development starts prevents the chaos that derails 70% of software projects.

What Happens After Launch?

Development doesn't end at deployment. Maintenance costs run 15-25% of initial development costs annually. Monthly expenses range from $5,000 to $50,000+, depending on complexity, user base, and support requirements.

Over the software's lifetime, maintenance often represents 50-80% of the total cost of ownership. Security patches, bug fixes, performance optimisation, feature enhancements, and compatibility updates never stop.

Technical debt compounds like financial debt. Development shortcuts taken to meet deadlines become exponentially more expensive to fix later. Plan for ongoing investment or watch your software decay into legacy liability.

The Bottom Line

Software timelines depend on scope clarity, team capability, and stakeholder discipline. MVPs take 2-4 months. Full applications take 6-12 months. Enterprise systems take 12-24+ months.

Want faster delivery? Bespoke application define requirements clearly, start with MVP scope, use proven third-party services, maintain disciplined change control, and hire appropriately-sized teams with relevant expertise.

Or ignore these factors and join the 70% of software projects that miss deadlines, exceed budgets, and deliver disappointment.