Milestone billing and NET terms for software projects

By Marco Lopes · December 22, 2024 · Business & Culture

Payment terms are part of project design. They influence when we reserve a team, how we divide work, what counts as finished, and how confidently everyone can plan the next release.

At Kordspace, our work spans software, AI, Web3, hardware, and design. Those disciplines have different delivery risks, but they share one commercial requirement: we need a clear connection between work completed, evidence delivered, and payment due.

Milestone billing creates that connection. NET terms define the time allowed to pay an invoice. Used together, they can make a remote collaboration predictable without turning every sprint into a financial negotiation.

Here is how we approach the conversation, and what we recommend putting in writing before work begins.

Separate milestones, invoices, and payment deadlines

These three concepts are related, but they are not interchangeable.

A milestone is an agreed delivery checkpoint. An invoice trigger is the event that permits billing. A payment term determines when that invoice becomes payable.

For example, we might agree that a tested integration is a milestone, written acceptance triggers its invoice, and payment is due NET 15 from the invoice date.

NET 15 generally means the full invoiced amount is due within 15 calendar days. NET 30 generally means 30 calendar days. We still spell out the convention, including treatment of weekends and public holidays, rather than relying on shorthand.

We also identify whether the clock starts at issuance, receipt, acceptance, or entry into a procurement portal. Those alternatives can produce very different cash-flow outcomes.

Choose a billing model that fits the uncertainty

Milestone billing works best when we can describe bounded deliverables and evaluate them objectively. A design system, a production-ready API, or a defined hardware prototype can fit that structure.

It becomes less reliable when the project is mostly discovery. Early AI experiments, unfamiliar device integrations, and legacy-system investigations may reveal the work rather than simply execute it.

In those cases, we prefer a paid discovery phase followed by a better-informed delivery agreement. Another option is capped time-and-materials billing, with regular reporting and an explicit decision point before further spending.

We do not treat fixed milestones as a cure for unknown requirements. The commercial model should make uncertainty visible, not hide it inside a promise that neither team can evaluate fairly.

Write milestones around outcomes, not activity

“Development complete” sounds useful until we ask what it includes. Does it mean merged code, a staging deployment, security review, documentation, or production availability?

A stronger milestone names the deliverable, environment, acceptance checks, exclusions, and evidence we will provide.

For an account-management feature, we might specify registration, sign-in, password reset, and role-based access in the agreed staging environment. Acceptance evidence could include a demonstration, test results, and a documented list of known non-blocking issues.

We also separate defects from new requests. A broken agreed workflow is a defect. Adding another authentication provider is normally a scope change unless it was already included.

That distinction protects quality while preventing acceptance from becoming an open-ended opportunity to expand the project.

Use a payment schedule that funds the work

A payment schedule should reflect delivery effort and exposure, not simply divide the total into equal pieces.

For illustration, a hypothetical $60,000 engagement could use this structure:

• 20%, $12,000: kickoff payment, due before we reserve the delivery slot and begin work.
• 30%, $18,000: accepted discovery and architecture package, including the agreed prototype.
• 30%, $18,000: accepted implementation in staging against the documented test plan.
• 20%, $12,000: accepted launch and handover package.

These are example commercial terms, not a universal Kordspace price or policy. We would adjust the allocation if implementation carries most of the cost, specialist equipment must be ordered early, or discovery is contracted separately.

The important principle is to avoid financing nearly the entire engagement while waiting for one final approval. Equally, clients should see meaningful evidence before paying the later installments.

Make acceptance a short, observable process

We recommend a defined review window, often expressed in business days, with one named approver and one place to record feedback.

A practical process is straightforward: we submit the deliverable and its evidence, the client checks it against the agreed criteria, and any rejection identifies the specific unmet requirements. We correct in-scope defects and resubmit the affected work.

We also agree whether minor issues prevent acceptance or move into a documented follow-up list. Without that distinction, a small cosmetic adjustment can hold up payment for an otherwise usable release.

Silence should have an agreed consequence, not an improvised one. Some contracts use deemed acceptance after a review window and reminder; others use an escalation process. We have the relevant language reviewed for the applicable jurisdiction rather than assuming silence always means approval.

Negotiate NET terms alongside the schedule

A milestone-based project can still create a long funding gap. If acceptance takes two weeks and an invoice then carries NET 30, payment may arrive well after the underlying work was completed.

Before kickoff, we map the whole sequence: delivery, review, invoice submission, procurement validation, and payment processing. We ask about purchase orders, vendor onboarding, payment runs, and any required invoice fields.

Where longer NET terms are unavoidable, we can discuss smaller milestones, an upfront payment, monthly progress billing, or pricing that reflects the financing burden. The right answer depends on project size and risk.

We avoid promising one schedule while quietly assuming faster payment than the contract allows. A workable agreement needs both the delivery calendar and the cash calendar to make sense.

Invoice clearly and remove administrative friction

A correct invoice is part of delivery operations. We include the contracting entity, billing address, tax information where applicable, purchase-order reference, milestone description, amount, currency, payment instructions, and an explicit due date.

We also specify whether fees exclude applicable taxes, how approved expenses are billed, and who covers transfer or currency-conversion charges.

For example, if the agreement uses NET 15 from the invoice date, a December 2 invoice would ordinarily show December 17 as its due date, subject to the agreed calendar rules. We prefer that visible date to leaving accounts payable to interpret “NET 15.”

Remote work makes routing especially important. We send invoices to the actual finance contact or required portal, not only to the person attending product reviews.

Treat scope changes as commercial decisions

When requirements change, we document the effect before committing to the additional work. A lightweight change request should state what changes, why, the price or estimation basis, and the impact on milestones and deadlines.

Sometimes we can exchange one planned feature for another without changing the budget. Sometimes a new dependency means the original acceptance date is no longer realistic. Both outcomes deserve written agreement.

We also record client-side dependencies: credentials, content, hardware access, stakeholder decisions, and third-party approvals. If those inputs arrive late, the agreement should explain how we reschedule work and handle reserved capacity.

We do not automatically label every delay billable. We make the consequences explicit so neither side discovers a new commercial rule halfway through delivery.

Keep cloud and third-party costs visible

Our preferred cloud platform is Google Cloud, and we also work with AWS and Azure. Whichever platform we use, infrastructure consumption should not disappear inside an ambiguous milestone fee.

Where practical, we deploy into client-owned accounts with appropriate access controls. That gives the client direct visibility into billing and reduces ownership problems at handover.

We distinguish professional fees from cloud usage, model API charges, software licenses, transaction fees, and other external costs. If we purchase something on the client's behalf, we agree on approval thresholds, reimbursement timing, and any handling charge in advance.

Budgets, alerts, quotas, and suitable service limits help manage exposure. We do not present budget alerts alone as a guarantee that spending will stop automatically.

Adapt acceptance to AI, Web3, hardware, and design

Different disciplines need different evidence.

For AI work, we define evaluation datasets, measurement methods, operating constraints, and agreed performance thresholds. We avoid promising universal accuracy or making payment depend on an undefined judgment that a model feels intelligent enough.

For Web3 work, we distinguish implementation, deployment, independent review, and any audit remediation. We identify who funds network fees and which external approvals affect launch.

For hardware, procurement and fabrication may require earlier payments than software delivery. We specify prototype quantities, test conditions, component substitutions, shipping responsibilities, and the difference between a prototype and a production-ready product.

For design, we define the artifacts, included review rounds, decision-makers, and handoff format. “We like it” is not enough of an acceptance framework on its own.

Plan for overdue payments without escalating unnecessarily

When an invoice becomes overdue, we start by checking for administrative problems. A missing purchase order or incorrect legal entity can be resolved more constructively than a dispute framed around bad intent.

The agreement should still define reminders, escalation, any permitted late charges, and a notice period before pausing work. We also agree how a pause affects delivery dates and team availability.

We never treat nonpayment as permission to damage systems, delete data, or quietly disable a production service. Contractual remedies need to be proportionate and lawful.

For a genuine invoice dispute, we aim to identify the contested amount and have undisputed amounts paid on time. That keeps one disagreement from unnecessarily freezing the entire relationship.

Connect final payment with a usable handover

Final delivery should include more than a launch announcement. We define the relevant repository access, deployment instructions, design files, infrastructure documentation, operating notes, and knowledge-transfer sessions.

The contract should also explain ownership and licensing: what is pre-existing, what is newly created, what third-party terms apply, and whether assignment of project-specific rights depends on payment. We keep client data ownership and access separate from commercial leverage.

Warranty obligations, maintenance, and ongoing support deserve their own boundaries. Launch acceptance should not imply unlimited future development.

We recommend professional legal and accounting advice for contract, tax, and collection questions, especially across borders.

A short pre-kickoff checklist

Before we schedule delivery, we confirm:

• Each milestone has a deliverable, acceptance criteria, and a named approver.
• Review windows, invoice triggers, NET terms, and due-date rules are explicit.
• Deposits, taxes, currencies, expenses, and third-party costs are covered.
• Scope changes and client dependencies have a written process.
• Procurement requirements and finance contacts are ready.
• Overdue-payment procedures, ownership, and handover obligations are agreed.

Clear billing terms are not separate from a good working relationship; they help sustain it. If we can define the work, the evidence, and the payment path together, we can spend more time building and less time interpreting paperwork. To discuss an engagement with Kordspace, start a project, or explore our services pages to see where we can collaborate.