Step 1
Define the decision
Your service sends who is asking, what they need, which policy version applies, and channel context. The format is the same for live API calls and offline packets.
How do HMRC services verify tax status without storing taxpayer records?
Tax, agent, and cross-government eligibility without PII retention.
Short answer: AffixIO returns yes or no on filing status, agent authorisation, and cross-government signals from HMRC-held sources - without copying full taxpayer records into partner or analytics systems.
Stateless verification · No standing PII store · ML-DSA ready
Programme context
HMRC interacts with citizens and businesses at very large scale: Self Assessment, PAYE, VAT, customs, and compliance. Many journeys need a definitive answer to a narrow question, not a copy of someone's tax record.
What teams are solving
Analytics environments, third-party agents, and cross-department credits create pressure to replicate tax and identity data widely. That conflicts with minimisation duties and increases operational risk.
AffixIO approach: AffixIO returns bracket, registration, or entitlement signals as yes or no with proof. Intermediary authorisation and fraud controls can consume the same API without a central honeypot at the verifier.
Where verification applies
- Tax status and bracket checks
Confirm status for consented third-party services without returning full records.
- Agent and intermediary authorisation
Verify that a tax agent may act for a taxpayer using cryptographic consent proofs.
- Fraud and duplicate identity
Cross-reference authoritative signals while limiting replicated PII in analytics.
- Benefits and credits interfaces
Support DWP and local authority handoffs with tax-linked eligibility.
- International reporting
Residency and status checks aligned with reporting obligations.
From request to verified outcome
The same three-step model used across AffixIO applies here: describe the decision, evaluate against sources you control, return yes or no with proof.
Step 2
Evaluate against authority
Checks run against registries and rules you authorise. Sensitive fields stay in systems you already operate wherever the design allows.
Step 3
Return yes or no with proof
The response is explicit, signed where required, and suitable for audit or partner handoff. AffixIO does not retain the request after the decision.
Where AffixIO sits in your stack
A thin stateless layer between citizen channels and core departmental systems. It answers eligibility questions; it does not replace case management, payments, or identity providers.
Your channelsGOV.UK services, contact centres, field applications, partner APIs, and automated agents.
AffixIOStateless verification via API and SDK. Binary outcomes with cryptographic proof.
Your core systemsDepartmental registries, identity, payments, HR, and case tools you already accredit.
Further reading: technical architecture, what AffixIO is, government data integration.
What you can implement
Consent-bound checks
Decisions tied to explicit taxpayer consent where required.
High-volume API
Horizontally scaled eligibility for peak filing periods.
Fraud-resistant signals
Binary outcomes for duplicate and anomaly workflows.
Example response (illustrative)
{
"eligible": true,
"proof": "<signed verification artefact>",
"decision_id": "dec_…",
"evaluated_at": "2026-05-15T12:00:00Z"
}
OpenAPI documentation: api.affix-io.com. Integrate via REST, webhooks, or SDKs.
How teams deploy
Managed API
Connect through your API gateway with TLS, mutual authentication where required, and departmental logging.
Self-hosted
Run inside your accredited boundary when policy requires on-premise or private cloud.
Offline and edge
Validate signed proofs locally where connectivity is limited. See offline verification.
Agentic channels
Machine clients receive the same binary signals as citizen channels. See M2M verification.
Cryptography and data handling
Built for long-lived programmes that must plan beyond legacy signatures and minimise data held at the verification boundary.
Stateless by design
No long-term store of who asked or the attributes inside a request. Supports proportionate DPIA narratives.
ML-DSA ready
Artefacts can use Module-Lattice-Based Digital Signature Algorithm (ML-DSA), aligned with NIST post-quantum direction, with optional HSM-backed key ceremonies.
Zero-knowledge outcomes
Where policy allows, demonstrate that a rule evaluated to yes without exporting underlying registry content.
Patent pending: AffixIO verification pipeline protected under GB2510622.0 (pending).
UK regulatory alignment
- UK GDPR and Data Protection Act 2018
- Government Security Classifications (OFFICIAL patterns; higher via your deployment model)
- NCSC cloud security principles
- Service Standard compatible citizen journeys
- Pseudonymised audit metadata for review
See GDPR compliance and privacy policy.
Common questions
Does AffixIO store citizen personal data?
No. AffixIO is stateless verification infrastructure. It evaluates a request against sources you authorise and returns a decision with proof. It does not maintain a standing database of citizens or request payloads.
Can this run offline for field teams?
Yes. Signed proofs can be validated where connectivity is limited, with reconciliation when the device or site is back online. This pattern is used across offline payment and access programmes on affix-io.com.
How does ML-DSA fit in?
Long-lived verification artefacts can be bound with ML-DSA (Module-Lattice-Based Digital Signature Algorithm), supporting post-quantum planning. HSM-backed ceremonies are available where your security policy requires them.
Speak with our team
Share your channel mix, assurance constraints, and first use case. We will respond with a practical integration outline.
AffixIO is an independent technology provider. References to UK departments and agencies describe integration patterns for eligible programmes; they do not imply endorsement. Operational deployment is subject to your organisation's assurance, procurement, and data-sharing agreements.