Tax Code "Rule-as-Code" Engine

The Tax Code Rule-as-Code Engine lets tax law specialists write rules in a structured, readable format that is tied clause by clause to the statute, regulation or guidance it implements. Each rule is tested against worked examples, reviewed by counsel and released as a versioned, machine-readable package that downstream processing systems consume. The link from legal text to running logic stays visible for every version, so reviewers can see what changed and why.

The problem it solves

When tax law changes, policy specialists describe the change in documents, developers interpret those documents into code in several processing systems, and testers try to confirm the result matches the law. Each hand-off is a chance for the meaning to drift. The same rule can be implemented differently in different systems, effective dates are tracked separately from the logic, and when a question arises about why a calculation behaves as it does, tracing it back to the legal text means reading code and old requirement documents side by side.

Who it’s for

• Tax administration agencies implementing changes to tax law and guidance
• Tax law specialists and policy analysts who interpret new provisions
• Counsel who review the legal reading of each rule
• Engineering teams who maintain tax processing and forms systems
• Testing, audit and oversight staff who need to trace logic to law

1. DraftA tax law specialist opens the provision being implemented and writes the rule in a structured format of definitions, conditions, calculations and effective dates, with each part linked to the clause it comes from.
2. TestEach rule is run against worked examples written by the specialist, including edge cases and examples from published guidance, so the logic is checked before anyone downstream relies on it.
3. ReviewCounsel and a second specialist review the rule beside its legal source, the interpretation notes and the test results, and approve or return it.
4. PublishApproved rule versions are released as a versioned, machine-readable package that processing systems consume through an API or file export, with release notes describing what changed.

Structured rule format

Rules are written as definitions, conditions, calculations and effective dates in a format specialists can read and processing systems can run.

Clause-level citations

Every part of a rule links to the clause of statute, regulation or guidance it implements, and the link is kept across versions.

Effective dating

Rules carry effective and end dates, and transition provisions are modeled explicitly, so the right version applies to each tax period.

Worked-example testing

Specialists write examples with expected results, and every rule change is run against the full example set.

Step-by-step trace

Each result can be explained step by step, showing the conditions met, values used and the clause behind each step.

Version comparison

Compare two versions of a rule to see changed conditions, calculations, dates and citations, and which examples now give a different result.

Review and approval

Clause-level comments, recorded interpretation questions and answers, and separate approvals for the legal reading and for release.

Shared definitions

Terms used across many provisions are defined once and referenced, so a change to a definition shows every rule it affects.

Release packages

Approved versions published as versioned packages with release notes, for consumption by API or file export.

Impact view

Before release, see which rules, forms and consuming systems a change touches, from the dependencies recorded in the engine.

Synthetic test data

Worked examples use constructed scenarios rather than real return information, so testing does not require access to taxpayer data.

Audit trail

Every edit, test run, comment, approval and release recorded with the person and time.

Tax law specialist

Drafts rules, writes worked examples and raises interpretation questions

Legal reviewer

Reviews the reading of the law in each rule and approves or returns it

Rules engineer

Maintains shared definitions, integrations and the rule format, without approving legal readings

Release manager

Groups approved versions into releases and promotes them to consuming systems

Consuming system team

Reads released rules and runs their own tests against test-channel packages

Auditor or oversight reviewer (read-only)

Views rules, versions, tests, approvals and the audit trail, with no ability to change them

Tax processing systems

Released rule packages are consumed by your processing systems through the engine's API or a scheduled file export, in a format agreed during implementation.

Legal source library

Statutory, regulatory and guidance text loaded from the sources your agency uses, with versions kept as the text changes.

Source control and build pipelines

Rule packages can be exported to your source control and continuous integration tools so consuming teams test them like any other dependency.

Requirements and work tracking

Rule changes can be linked to the work items your agency uses to manage legislative implementation.

Forms and instructions

Rule references can be shared with the teams that produce forms and instructions, so they can check that the published guidance and the logic agree.

Single sign-on

Staff sign in through your agency's identity provider, including PIV-based authentication where your provider supports it.

Work API

Rule, version, test and approval data available to your reporting tools through the Moraph Work API.

Hosted in the United States

Rules, examples and review records are hosted in the United States region.

Cleared support lane

Support tickets from federal clients are routed only to US citizens with active security clearances.

Access by role

Drafting, legal approval and release are separate permissions, and unreleased rules can be limited to the people working on them.

Encryption under controlled keys

Client data is encrypted with keys our staff cannot access without explicit, time-bound authorization.

Complete audit trail

Every edit, test, approval and release is recorded with the user and time, and cannot be edited.

Independent audits

Moraph's controls are covered by its SOC 2 Type II report and ISO/IEC 27001 certification, available through the Trust Center.

Moraph cloud, United States

Hosted in the United States region, with data kept in the US.

Dedicated environment

A single-tenant environment for agencies that require isolation, scoped in the proposal.

Rule packages run in your systems

Released packages are executed by your own processing systems or by an execution component installed in your environment, so production calculations do not depend on Moraph's cloud.

With a managed service

Optionally run alongside a Moraph managed service for administration, rule-engineering support and integration support.

Scope and pilot provisions

We agree with your policy and engineering leads which provisions to model first, usually a recent change with known expected results.

Rule format and conventions

Drafting conventions, shared definitions and citation styles are agreed with your specialists and counsel, and documented.

Legal source loading

The statutory, regulatory and guidance text in scope is loaded and versioned, with your team confirming the sources.

Consuming system integration

The package format and delivery method are agreed with one consuming system team, and their tests are run against the first release.

Roles and approvals

Roles, review steps and approvers are configured to match your agency's procedures for legal review and release.

Training and handover

Specialists, reviewers and engineers are trained on drafting, testing and release, and Moraph works alongside your team on the first provisions.

• It does not interpret the law for your agency. Every rule reflects the reading of your specialists and counsel, and Moraph does not provide tax or legal advice.
• It does not process returns or hold taxpayer accounts. Your processing systems run the released rules.
• Some provisions depend on judgment, facts and circumstances that cannot be reduced to conditions and calculations; these are recorded as inputs a person or system must supply, not decided by the engine.
• A rule is only as reliable as its worked examples. Testing shows the rule matches the examples written, not that the examples cover every case.
• Moraph holds no FedRAMP authorization for this product. We provide control documentation to support your agency's own authorization decision.
• Existing logic in legacy processing systems is not converted automatically; provisions are modeled in the engine as your agency chooses to bring them across.
• Consuming systems must be changed to read the released packages, and that work sits with the teams that own them.
• It is designed for tax provisions. Other areas of law can be modeled but are outside the conventions delivered at implementation.

• Ask a specialist to model a recent provision and judge whether counsel could review it without help
• Check that every step of a rule traces to a specific clause
• Write edge-case examples, including a transition period, and review how failures are explained
• Compare two versions of a rule and confirm the differences shown are complete
• Have an engineering team consume a test release in a non-production system
• Confirm role separation: who can draft, approve the legal reading and release