Every growing business eventually faces this question: should we buy off-the-shelf software and adapt our processes, or build something custom that fits how we actually work?
The stakes are high. Choose wrong and you'll waste years working around limitations, or spend a fortune building something you could have bought for a fraction of the cost.
Here's a framework for making the decision—based on five factors that actually matter.
Factor 1: Process Uniqueness
Ask yourself: do we compete on how we run this process?
If your customer service approach is identical to every other company in your industry, buy software. You're not gaining competitive advantage from the process—you just need it to work reliably and cheaply.
If your process is genuinely different—a unique methodology, proprietary workflows, or approaches that differentiate you from competitors—custom starts making sense. Off-the-shelf tools will force you to work like everyone else, which defeats the purpose.
Buy signal: "Our process is pretty standard, we just need to do it efficiently." Build signal: "Our process is our competitive advantage, we can't compromise it."
Most processes fall into the first category. Be honest with yourself—is your accounts payable process really unique, or does it just feel that way because it's yours?
Factor 2: Integration Requirements
Modern businesses run on data flowing between systems. The question is how complex that flow needs to be.
Off-the-shelf software typically offers:
- Native integrations with popular platforms (QuickBooks, Salesforce, etc.)
- API access for custom connections
- Zapier/Make compatibility for simple automations
For most SMEs, this is enough. You can connect your CRM to your accounting system without writing code.
But some integration needs are genuinely complex:
- Real-time synchronisation across multiple systems
- Custom business logic that must execute during data transfer
- Legacy systems with limited API capability
- Regulatory requirements for data handling
If your integration requirements are complex and core to operations, a custom software development agency or web development consultancy becomes the practical option.
Buy signal: "We need our systems to talk to each other." Build signal: "We need our systems to talk to each other in very specific ways that no existing tool supports."
Factor 3: Total Cost of Ownership
The purchase price is the least important number. What matters is total cost over time:
Off-the-shelf costs:
- Monthly/annual subscription fees (these often increase)
- Per-user licensing (scales with headcount)
- Upgrade charges for premium features
- Training and onboarding
- Workarounds for missing features (manual processes, additional tools)
- Switching costs when you outgrow it
Custom software costs:
- Development (one-time, typically £10,000-£75,000 for SME applications)
- Hosting and infrastructure (often under £100/month)
- Maintenance and updates (10-15% of development cost annually)
- No per-user fees—scale without penalty
- Evolution costs as needs change
For small teams with standard needs, off-the-shelf almost always wins on cost. The economics shift when:
- You have many users (per-seat licensing gets expensive)
- You need features that only exist in enterprise tiers
- You're paying for multiple tools that could be consolidated
- Workarounds consume significant staff time
Factor 4: Speed to Value
Off-the-shelf software is ready today. Sign up, configure, and start using it. Time to value: days or weeks.
Custom software takes time to build. Even a simple application takes 8-12 weeks when working with a software development agency in London or elsewhere. Complex projects take longer. Time to value: months.
If you need something working next week, buy.
If your current situation is painful but stable, and you're making a long-term decision, build time matters less. A few months of development followed by years of perfect-fit operation beats years of fighting inadequate tools.
Buy signal: "We needed this solved yesterday." Build signal: "We've needed this solved for years and we'll need it solved for years more."
Factor 5: Control and Dependency
When you buy software, you accept dependency:
- Features change without your input
- Pricing increases happen annually
- If the vendor goes bust or gets acquired, you scramble
- Your data lives on someone else's servers
- Roadmap priorities aren't yours to set
For most processes, this dependency is acceptable. The vendor's job is to make the software better; you benefit without effort.
But for core business processes, dependency creates risk. If the software you run your entire operation on gets discontinued, what happens?
Custom software means:
- You own the code
- You control the roadmap
- Your data stays where you want it
- No vendor lock-in
- Full flexibility to modify as needed
Buy signal: "This is important but not existential for our business." Build signal: "Our entire operation depends on this working exactly how we need it."
The Decision Matrix
Plot your situation against all five factors:
| Factor | Buy | Build | |--------|-----|-------| | Process | Standard | Unique/differentiating | | Integrations | Simple | Complex/specific | | Total cost | Low volume, standard features | High volume, consolidated | | Speed | Urgent | Can wait for right solution | | Control | Acceptable dependency | Need full ownership |
If you score mostly "Buy," buy something. Stop romanticising custom software—it's expensive and slow compared to proven tools.
If you score mostly "Build," take that seriously. A web development agency, software development consultancy, or bespoke software partner in London or across the UK can build exactly what you need.
Mixed scores require judgment. But at least you're now making the decision based on factors that actually matter, not sales pitches or assumptions.
The Middle Ground
Sometimes the answer is neither pure buy nor pure build:
Customise off-the-shelf platforms like Salesforce or HubSpot offer extensive customisation. You get stability with configuration that fits.
Build bridges by keeping your off-the-shelf tools but building custom integrations around them.
Buy then build starts with off-the-shelf to prove the concept, then builds custom once you understand requirements deeply.
The right answer for your business depends on your specific situation. But now you have a framework to find it.