A comprehensive comparison of building custom software versus subscribing to SaaS solutions. Understand the pros, cons, costs, and when each approach makes sense for your business.
Custom software (also called bespoke software) is built specifically for your business. A development team creates software designed around your exact requirements, workflows, and processes. You own the software and can modify it as your needs change.
SaaS (Software as a Service) is pre-built software that you subscribe to, typically paying monthly or annually. The software provider hosts and maintains the application. You access it through a web browser. Examples include Salesforce (CRM), Shopify (e-commerce), and Xero (accounting).
| Factor | Custom Software | SaaS |
|---|---|---|
| Upfront Cost | High (development investment) | Low (subscription starts immediately) |
| Ongoing Cost | Lower (hosting + maintenance) | Higher (monthly fees that compound) |
| Customisation | Unlimited (built to your spec) | Limited (configuration options only) |
| Time to Deploy | Months (development required) | Days/weeks (already built) |
| Ownership | You own the software | Vendor owns, you rent access |
| Data Control | Full control, your servers | Vendor controls data hosting |
| Integration | Can integrate with anything | Limited to available integrations |
| Scalability | Scale as needed | Pay more as you scale |
| Vendor Dependence | None (you own it) | High (vendor can change terms/prices) |
You have unique processes that standard software cannot accommodate, need deep integration with existing systems, have specific security or compliance requirements, or plan to use the software as a competitive advantage.
You need to deploy quickly, have standard requirements that match the SaaS offering, want to minimise upfront investment, or prefer the vendor to handle maintenance and updates.
When comparing costs, look beyond the obvious. SaaS subscription fees compound over time and often increase. Custom software has upfront development costs but lower ongoing costs. Calculate the total cost over 3-5 years, not just Year 1.
Consider a business with 50 users needing a specialised business application:
| Cost Type | Custom Software | SaaS ($50/user/month) |
|---|---|---|
| Year 1 | £80,000 (development) + £5,000 (hosting) | £30,000 (subscriptions) |
| Year 2 | £10,000 (maintenance + hosting) | £30,000 (subscriptions) |
| Year 3 | £10,000 (maintenance + hosting) | £33,000 (price increase) |
| Year 4 | £10,000 (maintenance + hosting) | £33,000 (subscriptions) |
| Year 5 | £10,000 (maintenance + hosting) | £36,000 (price increase) |
| 5-Year Total | £125,000 | £162,000 |
In this example, custom software costs less over 5 years despite the higher initial investment. The break-even point is typically around Year 3-4.
Many businesses use a combination:
Custom software is built specifically for your business and owned outright, offering an exact fit and no per-user licence fees. SaaS is pre-built and rented by subscription, offering a lower upfront cost but limited customisation and ongoing fees.
Custom software makes sense when your processes are unique, you need deep integrations with other systems, you want full ownership and control, or off-the-shelf tools force costly workarounds.
SaaS is usually better for standard, non-differentiating functions such as email, basic accounting or generic CRM, where a proven product exists, you need to start quickly, and the subscription cost is acceptable long-term.
Custom software has a higher upfront cost but no recurring per-user licence fees, so over several years the total cost of ownership can be lower, especially as user numbers grow. SaaS is cheaper to start but costs scale with users and time.
We can help you evaluate your requirements and recommend the best approach. Whether custom software, SaaS, or a hybrid solution, we'll help you make the right choice.
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