Fixed price and time and materials answer how you pay for development; they do not tell you whether the scope is sensible. A fixed price works better when both sides can describe the accepted result. Time and materials can fit work that needs discovery and reprioritization, provided spending and decisions remain visible.
A separate choice is who delivers: an agency, a freelancer, your employees or a combination. An agency can work under different commercial models. This guide separates those decisions so you can compare responsibility, uncertainty and ownership without treating an inexpensive quote as a complete agreement.
Related service: Custom software development services- 01List known requirements and material unknowns.
- 02Choose who owns product and delivery decisions.
- 03Compare a bounded release with a time-boxed investigation.
- 04Agree evidence, spending controls and change handling.
- 05Review working results before authorizing the next stage.
SECTION 01
Compare the control each pricing model gives you
With fixed price, the buyer and supplier agree a price for described work. The useful question is what counts as complete: which user journey, records, integrations and tests? A vague promise to build a dashboard leaves plenty of disagreement even when the amount is fixed.
Time and materials charges for agreed effort and expenses. It allows priorities to change, but an open-ended backlog is not a spending plan. Request an approved budget boundary, forecast-to-complete updates and a decision point before that boundary is reached. A spending cap does not by itself guarantee that every feature will fit.
The UK government's agile contracting guidance describes several commercial approaches and emphasizes the effect of uncertainty. It is a useful procurement reference, not a universal contract or a statement of U.S. law. The comparison here concerns delivery decisions; have your own agreement reviewed for its circumstances.
| Model | Useful starting condition | Control to request |
|---|---|---|
| Fixed-price release | A coherent workflow and acceptance cases are understood | Assumptions, exclusions and an approved change route |
| Time and materials | Important requirements will evolve through working evidence | Effort reporting, forecast and spending approval boundary |
| Discovery followed by a release | The unknown integration or workflow could change the estimate | A time box and reusable discovery outputs |
SECTION 02
Agency, freelancer or an in-house team?
A freelancer can fit a focused task when your business already has someone to manage scope, reviews and deployment. Ask who covers design, testing and maintenance rather than assuming those jobs disappear. The relevant comparison is the whole delivery arrangement, not one person's rate against an agency total.
An agency can coordinate several disciplines for a defined project, but confirm which people and responsibilities are actually included. An in-house team can provide continuing product context when the work is central and ongoing. It also requires hiring, management, tools and a plan for skills the team does not have.
A combined model might keep your product owner in-house while an agency builds a bounded release. GOV.UK's guidance on contractors stresses buying needed skills and maintaining internal responsibility. Catapult's offer here is project delivery; this guide does not advertise staff leasing or a fractional leadership service.
SECTION 03
Illustrative example: a known portal with an unknown connection
Suppose you need a client to submit a request, upload a document and see staff approval. The screens and roles are understood, but nobody has verified the old CRM's write API. This is an illustrative decision, not a client case study or a priced package.
A short investigation can test the API using approved sample data and produce a mapping, failure cases and a recommendation. The later portal release can then be estimated against that evidence. If the API cannot perform the required update, you can choose an alternative before paying for a polished interface around an impossible handoff.
During development, a request to add electronic signing is a new decision, not automatically a defect. Ask for the change's scope, dependencies and effect on remaining work. A broken upload that fails an agreed acceptance test belongs in a different discussion. Keep that distinction visible in the decision log.
SECTION 04
Write down what your business receives
Source-code ownership and repository access are not identical. A project can contain custom code, open-source components and licensed services with different terms. Agree the rights and access your business receives, when it receives them, and what a future maintainer needs to deploy the application.
The handoff inventory should cover repositories, domains, hosting, databases, provider accounts, configuration instructions, backups and documentation. Identify recurring charges and who may authorize production changes. Do not make essential operations depend on an individual developer's personal account.
SECTION 05
Compare proposals on accepted work, not confident language
Send the same workflow and unknowns to shortlisted providers. Ask each to explain deliverables, assumptions, buyer responsibilities, review cadence and exit arrangements. A source of verified references can help evaluate a provider, but an agency's own comparison article is not independent evidence that it is the best.
For a remote engagement serving U.S. or other buyers, agree review overlap and escalation rather than assuming continuous availability. Compare implementation cost with subscriptions and support separately. Catapult provides a scope-based quote; contact us for pricing once the proposed release and delivery responsibilities are clear.
SECTION 06
Frequently asked questions
Is fixed-price software development always cheaper?
No. Compare equivalent scope, uncertainty, exclusions and changes. A smaller headline price can omit work that another proposal includes, while unresolved requirements can change either model's final cost.
Should a small business hire an agency or a freelancer?
Choose by the work and your internal capacity. A focused task may suit a freelancer; a project needing coordinated design, development, testing and launch may suit an agency. Confirm who owns every responsibility.
Does paying for development mean we own all the code?
Do not assume it. Confirm the agreed rights, repository access, licensed components and handoff terms before starting. Receiving a working application alone does not establish those terms.
PRIMARY REFERENCES
Sources and further reading
These references cover the standards, platforms, or published prices discussed in the guide. Worked examples and checklists are our editorial guidance.
- Contracting for agile guidance noteGOV.UK
- Working with contractors or third partiesGOV.UK Service Manual
EDITORIAL METHOD
About this guide
We use AI to assist with drafting and editing. Catapult AI Work is responsible for the published content. Examples illustrate possible approaches; they are not client case studies unless identified as such.
Budget examples are not Catapult package prices. Check linked provider pages for current fees and plan limits before making a purchase.
Read the editorial policy