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Custom software development agreement

A software development agreement links technical specifications to the timetable, price, testing and code rights. The costliest disputes arise when parties use the same words — completed, bug, accepted — with different meanings.

specifications and milestones source code and IP change requests
Recommended structureMaster agreement + specifications + acceptance plan
Critical pointDistinguishing bugs from new requirements
Assets coveredCode, documentation, design, data and third-party components
01

Technical specifications become contractual obligations

The agreement must identify the specification version, deliverables and dependencies for which each party is responsible. Wording such as fully functional platform is insufficient without testing criteria and the environment in which they are checked.

For agile projects, the agreement can establish backlog prioritisation and budget consumption processes without pretending every function is known at signing.

02

Delivery, testing and acceptance

Acceptance must be a process, not silence with unclear effects. The test environment, test data, defect severity and point at which a version can enter production are defined.

  • Milestones: deliverables, date, price and dependencies for each stage.
  • Acceptance criteria: observable tests and expected results.
  • Defects: severity classification and remediation deadlines.
  • Change requests: estimation, approval and effect on budget and timetable.
  • Conditional acceptance: use with minor defects and a remediation list.
  • Handover: repository, build, keys, documentation and infrastructure access.
03

Who owns the code and project components

Copyright law protects a program’s expression, including source code and preparatory material, but invoice payment does not automatically assign all rights. The agreement must distinguish project-created code, pre-existing components, open-source libraries and third-party services.

An assignment or licence must specify rights, territory, duration, transfer timing and remuneration. An open-source licence inventory is maintained and obligations affecting product distribution are checked.

04

Security, warranty and life after launch

The agreement establishes secure development standards, vulnerability management, data access and incident notification. Where the product processes personal data, GDPR roles and provider instructions are addressed separately and specifically.

The Cyber Resilience Act applies in stages to products with digital elements: principal obligations apply from 11 December 2027, while certain reporting obligations for actively exploited vulnerabilities and severe incidents begin on 11 September 2026. Projects launched now must be designed with this transition in mind.

05

How we work together

  1. 01
    Mapping the service

    We clarify the product, users, technical workflows, commercial model and documents already in use.

  2. 02
    Legal analysis

    We establish the B2B or B2C regime, the parties’ roles, applicable legislation and risks to be allocated.

  3. 03
    Drafting and alignment

    We prepare the software project agreement and schedules and coordinate them with the interface, proposal, technical processes and annexes.

  4. 04
    Implementation

    We deliver the final version and a clear set of observations for publication, signature, configuration or operational use.

QUESTIONS

Frequently asked questions

Does the client own the code after payment?

Not automatically in every case. The effect depends on the agreement, rights involved, pre-existing components and Law No. 8/1996.

Is the technical proposal sufficient?

A proposal may describe price and functions but rarely adequately governs acceptance, IP, changes, liability, security and termination.

How is a bug distinguished from a new feature?

By reference to approved specifications and acceptance criteria. The agreement must state who classifies the request and how disagreements are resolved.

Need a software development agreement?

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