Choose SaaS when a maintained product supports your essential workflow at an acceptable lifetime cost. Choose custom software when important requirements remain unmet and the business can fund development and ongoing ownership. A hybrid can combine standard services with a focused custom workflow. Compare all three against the same requirements, time horizon and operating responsibilities.
This is a procurement decision, not a vote for a development method. SaaS describes a service delivery model; custom software describes how software is commissioned or built. A custom application can itself run as a hosted service. For this comparison, “SaaS” means subscribing to an existing vendor product.
Use this comparison after you have established the workflow problem and a shortlist of feasible options. If you cannot yet describe the gap or who owns it, complete an operational discovery first. The output here is a purchase decision record with comparable costs and supplier evidence.
Begin with mandatory scenarios
Define five to ten scenarios the chosen solution must complete. Include routine work and difficult cases: a partial order, cancelled booking, staff departure, disputed approval or unavailable integration. For each scenario, state the user, starting data, required outcome and evidence of success.
Separate mandatory requirements from preferences. A familiar button position should not carry the same weight as preventing one customer from accessing another customer's records. Demonstrate the scenarios using realistic sample data and record whether each option works as standard, needs configuration, needs development or cannot support the requirement.
Compare capability and responsibility together
| Decision area | Existing SaaS | Custom application | Hybrid |
|---|---|---|---|
| Initial availability | Core product already exists; implementation still needed | Requires discovery and delivery | Existing core plus a scoped extension |
| Workflow flexibility | Bounded by product and configuration | Can implement agreed rules | Unique rules in custom layer |
| Operations | Vendor runs platform; buyer manages use and configuration | Responsibilities must be assigned explicitly | Shared across vendors and integration owner |
| Exit | Depends on export and contract terms | Depends on code, documentation and transferable operations | Must cover both data and connections |
The UK Technology Code of Practice includes purchasing strategy, interoperability and lifecycle considerations. It is government guidance, but those questions provide useful procurement prompts for private businesses too.
Build a comparable total cost of ownership model
Use a consistent period, such as three years, and write the assumptions beside every line. Include initial implementation, migration, integration, licences, hosting, support, maintenance, internal administration, training and exit. Use actual supplier quotations where available; mark unquoted items as estimates.
For SaaS, check minimum seats, premium features, transaction limits, storage, API access and renewal assumptions. For custom software, include the operating service, security updates, dependency changes and planned enhancements. Compare equivalent outcomes: a small bespoke portal is not a fair price comparison with an entire enterprise suite.
An illustrative three-year comparison
The figures below are fictional planning inputs in pounds sterling, excluding VAT. They are neither market rates nor HINTX quotations. The example assumes similar functional scope and 36 months of operation from go-live; any pre-launch delay and bridging costs must be considered separately.
| Cost line | SaaS example | Custom example |
|---|---|---|
| Initial setup or development | £8,000 | £45,000 |
| Migration and integrations | £12,000 | £10,000 |
| Subscription or hosting for 36 months | £43,200 | £10,800 |
| Support and administration for 36 months | £14,400 | £21,600 |
| Planned changes and exit allowance | £6,000 | £9,000 |
| Total | £83,600 | £96,400 |
Here, SaaS is £12,800 lower on the stated assumptions. That conclusion changes if required features need a higher tier, the custom scope expands or support proves more expensive. Test low, expected and high usage instead of announcing a universal break-even month. If licensing depends on seats, model realistic headcount changes rather than assuming every employee requires the same licence.
Keep benefits separate from costs
Both options may improve the same workflow. Do not credit all process benefits to custom development while evaluating SaaS only on subscription spend. Record which option can produce each benefit, confidence in the estimate and the cost of delays.
If one option frees 15 staff hours monthly and another frees 18, compare the incremental three hours alongside other differences. Released capacity is not necessarily cash savings. Show how the organisation will use it, and avoid counting the same improvement under productivity, cost reduction and revenue growth.
Inspect security and supplier evidence
Ask both suppliers how they manage access, vulnerabilities, incidents, backups and recovery. Request evidence relevant to the service you will receive; a broad corporate statement may not describe the product configuration in your contract. Agree who handles account administration and what happens when a critical issue is reported.
NIST's Secure Software Development Framework provides a common basis for discussing development practices and vulnerability management. Referencing it is not proof of certification or assurance. Ask what practices the delivery team actually follows and which evidence it can supply.
Test the exit before signing
Request a sample export with related records and attachments. Check whether identifiers, histories and important metadata remain usable. For custom software, confirm source access, build instructions, deployment documentation and third-party licence dependencies. For either option, identify who can operate the service if the original supplier becomes unavailable.
GOV.UK's technology guidance treats flexibility and total ownership cost as important selection considerations. A practical test is asking a technically competent person unfamiliar with the product to inspect the handover material and identify what would prevent a transition.
Make a decision record the board can review
Summarise mandatory requirements, demonstrated fit, cost assumptions, unresolved risks and the chosen option. State what would cause a review, such as a major price change or a new operating model. A short record is more valuable than a weighted score whose inputs nobody trusts.
HINTX's TapIt portfolio documents a B2B ordering platform with buyer and supplier workflows. It illustrates custom product engineering, not a verified cost advantage over any vendor. Our software and SaaS development service can support requirements, implementation and scoped handover.
Frequently asked questions
Is SaaS always cheaper?
No. Compare required features, user growth, integrations and operating costs over the same period. There is no universal crossover point.
Does owning code eliminate vendor dependence?
No. You also need documentation, usable infrastructure access, transferable skills and clarity on third-party components.
When is a hybrid worth considering?
When a standard product handles most work and a bounded extension provides the important missing capability. Include integration support in the cost model.
Should a weighted score decide the purchase?
Use scoring to expose trade-offs after mandatory criteria are satisfied. A high total cannot compensate for a critical failed requirement.
Discuss your software options with HINTX using the workflows, cost assumptions and supplier evidence that matter to your business.
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