Fixed-Price Software Development for UK Companies

This guide is for a UK founder, operations lead, or procurement and legal reviewer about to commission a custom build from an offshore partner, once outsourcing to Vietnam is already the chosen route and the open question is whether to sign a fixed-price or a dedicated-team contract — and, having chosen fixed price, how to scope, contract and accept it. Netbase JSC wrote this page and offers fixed-price projects to UK companies.

In this guide

• Does fixed price fit your offshore project?
• Fixed price, time and materials, or dedicated team: which fits a UK buyer?
• Writing the scope and the acceptance criteria
• Change control: what happens when the scope needs to move
• What does UK GDPR require when the data moves to an offshore team?
• Governing law and IP assignment: questions for your own lawyer
• Working hours: Hanoi and the UK
• How Netbase works with UK clients
• From first call to accepted delivery
• Where AI fits
• What delivery record exists, and what does not
• Alternatives: who drafts the contract
• Limits of this guide
• Frequently asked questions
• Next step

Does fixed price fit your offshore project?

A fixed-price contract works when three things are true at signature: the scope can be written down in enough detail to test against, the project is short enough that a handful of change requests will not dominate it, and "done" can be defined as a pass/fail milestone rather than an open-ended judgement call. UK government sourcing guidance states the same constraint directly: fixed pricing needs "fixed scope," and "floating or variable scope is not suitable for fixed pricing" — work that cannot yet be estimated, or whose requirements will keep moving, belongs on a different pricing model until a discovery phase has narrowed it down. If any of the three conditions is missing, the right move is not to force a fixed-price quote; it is to run a short, separately scoped discovery phase first, then fix the price once the scope stops moving.

Fixed price, time and materials, or dedicated team: which fits a UK buyer?

A UK buyer does not have to choose once and commit for the life of the relationship. UK government agile-contracting guidance recommends treating discovery as time-and-materials "so that the provider is able to scope the requirement and give a more accurate cost," then moving to fixed-price sprints tracked by "burndown charts or the number of story points accepted," with a structure that allows exit without stranded costs. The same logic applies offshore.

Writing the scope and the acceptance criteria

A fixed-price scope document should read like a test plan, not a sales pitch: the features in, the features explicitly out, the integrations and their contracts, and a non-functional section (performance, browser or device support, accessibility) stated in numbers a tester can check against. Acceptance is tied to milestones, not to the final delivery date alone — each milestone has its own written criteria, and payment follows sign-off against those criteria rather than against elapsed time. Whoever drafts it, a named person on each side should review and own the document before signature.

Change control: what happens when the scope needs to move

Even a well-specified project meets a change mid-build. A UK buyer should expect, and ask for, a single written change-request process before signature: one point of contact who raises changes, a rule that nothing reaches the build team without going through that process, and a standard change-order format that states the new scope, the price delta and the date impact before the change is accepted. This is a governance habit, not a legal clause alone: the process only protects the budget if every request actually goes through it.

What does UK GDPR require when the data moves to an offshore team?

If the project involves personal data and an offshore team will process it, the UK company stays the controller and stays responsible for the transfer, even though a supplier carries it out. UK data-protection guidance describes a restricted transfer as one that needs "UK adequacy regulations; appropriate safeguards; or an exception," and if you rely on a safeguard, such as the International Data Transfer Agreement (IDTA), the guidance says you "must also ensure that you have completed a transfer risk assessment." This is not legal advice, but questions worth putting to a UK lawyer during contracting include: which data categories should the contract name, which transfer mechanism applies before any data moves, and where is the risk assessment kept?

Governing law and IP assignment: questions for your own lawyer

This is not legal advice; it is the short list of questions a UK company should put to its own solicitor before signing an offshore fixed-price contract: which country's law governs the contract and where disputes are resolved; when IP assigns to the buyer — on payment, on milestone acceptance, or only on final delivery; whether pre-existing supplier tools stay licensed rather than assigned; and what happens to the IP position if a milestone is disputed or the contract ends early. At Netbase, the client owns the IP created for its custom work, while Netbase's productized modules are licensed, not transferred; ask your lawyer whether any contract you are offered states this the same way.

Working hours: Hanoi and the UK

Vietnam runs on UTC+7 year-round; the UK is UTC+0 in winter and UTC+1 (British Summer Time) in summer, so the overlap narrows and widens with the clock change. A Hanoi team keeping standard office hours overlaps the UK morning for roughly two to three hours, enough for a short daily or twice-weekly sync if the rest of the communication is asynchronous: the written scope and change-request process above, recorded demos instead of live walkthroughs, and a single point of contact on each side.

How Netbase works with UK clients

Netbase delivers every engagement remotely from Hanoi and can engage clients in any country, including the UK, with no local UK office and no claim of one; the first contact is the CEO, Huy Nguyen (David), by WhatsApp or email. Contracts and invoices are issued by Netbase JSC, and payment is by bank transfer to Netbase JSC's company account or PayPal Business — stated as methods only, never a price or currency figure. Most projects are delivered on fixed-price contracts agreed after discovery, with milestone-based, monthly-retainer and KPI-linked terms also offered; see how that model runs as an offshore development center or a custom software development engagement.

What delivery record exists, and what does not

Netbase's six-step delivery lifecycle opens with discovery and strategic alignment, then team assembly and architecture planning, before agile execution starts — the same discovery-first sequence this guide recommends before fixing a price. Fixed price is Netbase's primary commercial model, with milestone-based, monthly-retainer and KPI-linked terms offered where a scope cannot be fixed up front. Delivery is remote from Hanoi, in English, for clients in any country, with the CEO as first contact and contracts and invoices issued by Netbase JSC.

What does not exist. Netbase has not published a UK office, a UK-registered entity, a named UK client, or a GBP price or day rate; none is claimed here. The fit test, the UK GDPR summary and the working-hours guidance above are a framework drawn from UK government and regulator guidance, not a Netbase benchmark, and no duration or price is attached to them as a Netbase commitment.

Alternatives: who drafts the contract

Whichever route drafts the paperwork, the scope, acceptance and change-control process above stay the same; a larger or more boutique Vietnam IT vendor changes how much governance the relationship needs, not whether these questions get asked.

Limits of this guide

• This is not legal advice. The governing-law and IP-assignment section lists questions to raise with your own solicitor; it does not state what any particular contract should say.
• No price, rate, day rate or GBP figure is published here for Netbase or for any third party; cost comparisons a UK buyer finds elsewhere are not reproduced.
• The working-hours overlap described is a general Hanoi-UK pattern, not a commitment to a specific meeting schedule, which is agreed per engagement.

Next step

See an anonymised manufacturing and logistics platform in Netbase's work portfolio, browse more delivery proof, or book a solution review with Netbase JSC's CEO to scope your own project before you fix a price.

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