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Qstamp / QTax
QTax

Tax records that cannot be quietly rewritten.

QTax is the tax integrity tool of the QGov branch of the Qstamp family. It seals every return, invoice, assessment and refund as it happens, so a tax authority, its auditors and the courts can prove that no record was altered, backdated or invented, while taxpayer data never leaves the authority.

Live flow

How QTax runs inside a tax administration.

Each step lights in turn as a record moves through it. Steps inside your systems never send content out. Only the anchor reaches the Quantova network, and only chain facts are public on QVMScan.

Live flowQTax, from tax intake to the explorer
  1. Your systemsTax intake systemA return arrives and is fingerprinted on receipt
  2. Your systemsFilingSigned with ML DSA under the intake key and linked to any amended filing
  3. Your systemsAssessmentSealed by a separate assessor key against the filing
  4. Your systemsRefund chainPaid by an officer key with its position and running total
  5. Quantova networkAnchorOne salted 32 byte commitment per batch, sent under record kind 1101 in a transaction signed with ML DSA 65
  6. PublicQVMScanFinal in about 0.2 seconds and indexed on the explorer under QTax, with no record content
  7. PublicAuditor or courtVerifies the whole chain without the systems of the authority
Inside your systemsQuantova networkPublic and verifiable
The challenge

Tax fraud lives in records that change after the fact.

Fictitious invoices

Invoices that were never issued are used to claim input tax and refunds, a pattern behind large scale VAT fraud.

Altered assessments

An assessment or penalty reduced after it was decided, with the change hidden in the records of the system that made it.

Unsupported refunds

A refund released without a valid assessment behind it, or released twice, and later hard to trace.

The QTax framework

Six stages, each sealed and linked.

Stage 1 · Registration

Taxpayer and system keys

Each tax office, each certified invoicing system and each authorised official receives a key under a mandate that names what it may file, assess or approve.

Stage 2 · Filing

Returns sealed on receipt

Every return and every amendment is fingerprinted when it is received and linked to the version before it, so a later edit or a backdated amendment is always visible.

Stage 3 · Invoicing

Invoices sealed when issued

Certified invoicing systems seal each electronic invoice at issue. The authority can confirm that an invoice a buyer claims is the same invoice the seller issued and reported, which exposes invoices that never existed.

Stage 4 · Assessment

Decisions signed by the assessor

Each assessment, adjustment and penalty is signed by the official authorised to make it and sealed with the filing it relates to.

Stage 5 · Refunds

Every refund linked to its assessment

A refund is released only against a sealed assessment that justifies it, and the payment itself is sealed, so a refund without a basis is detected.

Stage 6 · Audit

Independent review

Auditors and tribunals verify the full chain of a case, from filing to refund, without access to the systems of the tax authority and without trusting them.

Taxpayer privacy

Integrity of the record, confidentiality of the taxpayer.

Returns, invoices and taxpayer identities stay inside the systems of the tax authority and the certified invoicing systems. Only salted fingerprints are anchored, so nothing published can be linked to a taxpayer or used to confirm a guess about a return. QTax supports the move to real time digital invoice reporting, such as the European Union VAT in the Digital Age package, without adding any public disclosure of taxpayer data.

Status

Released, ready to pilot.

QTax 0.1.0 is published on npm as @quantovainc/qtax and on GitHub, after four rounds of security review and live testing on the Quantova network, where its anchors are indexed on QVMScan under record kind 1101. Tax authorities can integrate it today alongside the live Qstamp, QSign, QMandate and QLog SDKs. QTax proves that tax records are unchanged since they were sealed, who sealed them and when. It does not itself decide whether a return or a refund is lawful, which remains the work of the authority and the courts. The current releases anchor on the Quantova test network ahead of production use.