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15 MIN DELAYED market data · source + timestamp on hoverFTSE 100 8,214▲GBP/USD 1.2731▼EUR/GBP 0.8442UK Bank Rate 4.75%SONIA 4.70%GBP/EUR 1.1846REGNEXUS BOOKS — Know what happened. Know what happens next.GENESIS — Build. Authorise. Operate. Grow.SAFEGUARD — Safeguarding governance and controlLUMEN — Run learning at scaleREGNEXUS MAIL — Business communication infrastructure15 MIN DELAYED market data · source + timestamp on hoverFTSE 100 8,214▲GBP/USD 1.2731▼EUR/GBP 0.8442UK Bank Rate 4.75%SONIA 4.70%GBP/EUR 1.1846REGNEXUS BOOKS — Know what happened. Know what happens next.GENESIS — Build. Authorise. Operate. Grow.SAFEGUARD — Safeguarding governance and controlLUMEN — Run learning at scaleREGNEXUS MAIL — Business communication infrastructure
The Business Financial Control Platform

Know what happened.
Know what happens next.

RegNexus Books combines accounting, forecasting, financial control and decision intelligence in one deterministic financial platform.

AI does not decide your financial truth. Your financial truth is calculated. AI helps you understand it.

Start with RegNexus Books See it in action →
Books £49/mo · Books Pro £149/mo · Enterprise from £349/mo
LEDGER INTEGRITY · LIVE
CERTIFICATION · LIVE
CLAIMS · checking…
LAST VERIFIED · checking…
DETERMINISTIC CORE · ACTIVE
RegNexus BooksLIVE
Ask anything
The Platform

One financial system. Far more than accounting.

Deterministic Ledger

Financial truth calculated from governed rules — not generated.

Financial Intelligence

Ask your books; answers grounded in financial state.

Continuous Close

Close through the month, not at month-end.

Revenue Recognition

Contracts, obligations, deferred revenue, deterministic recognition.

Multi-Entity

Entities, eliminations, FX, consolidation, group reporting.

Horizon

Forecast, model and test tomorrow before you decide.

Frontier

Create evidence, verification and financial trust.

Nexus

Connect decisions to authority, agreements and execution.

See it in action

Watch Books think — then prove it.

A short product tour: a business event flows into deterministic truth, and AI explains it without ever posting.

● PRODUCT TOUR
RegNexus Books — 90-second tour
Video placeholder — drop the final MP4 / embed here
The Deterministic Difference

AI should explain your finances.
It should not invent them.

Business event
Intent
Financial compiler
Rules + controls
Deterministic financial truth
Ledger
— AI stops here —
AI explanation

Calculation, then interpretation.

RegNexus separates calculation from interpretation. Your financial truth is computed deterministically and traceably; AI is only ever permitted to explain it — never to author it.

FACT → TEST → EVIDENCE → VERDICT → AI EXPLANATION
The Architecture

Your financial system should do more than record the past.

Books

Know your business.
AccountingRevenueCashCloseTaxReportingMulti-entity

Horizon

See what happens next.
Digital TwinForecastingCounterfactualsDecision modellingVariance learning

Frontier

Prove what is true.
AuthorityEvidenceRule packsVerifiable claimsFinancial credentials

Nexus

Connect to the world around you.
ContinuumAccordCredenceConstellation
BOOKSFrom record → decision → proof → execution.
Horizon

Don't just forecast. Test the decision.

Model the counterfactual before you commit — deterministically, from your real financial state.

Explore Horizon →
What happens if sales fall 15% next quarter?
BASELINE
Cash£428,000
Runway17.2 months
SCENARIO · Revenue −15%
Cash£336,400
Runway13.7 months
DIFFERENCE
Cash−£91,600
Runway−3.5 months
Frontier · Live Certification

Don't take our claims on trust.

Financial truth should be provable. A transaction becomes evidence → authority → hash → credential → verification. And our own controls are certified continuously — if something fails, this panel changes.

✓ Source verified ✓ Authority verified ✓ Ledger proof verified ✓ Integrity chain verified
REGNEXUS CERTIFICATIONGREEN
Claims checked16
Claims passing16
Claims failing0
Ledger integrityPASS
Authority controlsPASS
Execution safeguardsPASS
Financial truth boundaryPASS
Last certificationchecking…

Live values are fed from the certification engine — not hard-coded marketing figures.

Nexus

Connect decisions to the world around your business.

Continuum

Forecast → actual → variance → learning.

Accord

Identity → capacity → authority → agreement → obligation.

Credence

Portable financial trust.

Constellation

The economic relationships around your business.

Built for the month. Ready for the year.

Continuous close and enterprise finance.

Continuous Close

Accruals · Prepayments · Reversals · Flux analysis · Close tasks

Revenue

Contracts · Milestones · Deferred revenue · Recognition

Enterprise

Multi-entity · Consolidation · Intercompany · FX · Dimensions · Approvals

Why switch

Move beyond traditional accounting software.

Traditional accounting
RegNexus Books
Reports
Answers
Historical records
Temporal financial state
Manual checking
Continuous controls
Forecast spreadsheet
Financial Digital Twin
AI-generated narrative
Deterministic truth + AI explanation
Periodic assurance
Continuous certification
One company view
Multi-entity financial control
Documents as evidence
Verifiable proof
Integrations

Connect without surrendering control.

Only production-supported providers are shown as live; pilots are labelled.

RegNexus
Books
HMRC
Open Banking
Companies House
Stripe
TrueLayer
SumUp
GoCardless
API · Webhooks
● LIVE — HMRC (MTD), Companies House, Open Banking (TrueLayer), API, Webhooks ● AVAILABLE — Stripe, SumUp ● CONTROLLED PILOT — GoCardless

We only show a provider as live where it is genuinely production-supported. Pilots are labelled.

Security & Control

Built to control who can see, decide and act.

Capability
Owner
Admin
Accountant
Bookkeeper
Viewer
Post journals
✓
✓
✓
✓
—
Approve (4-eyes)
✓
✓
—
—
—
File to HMRC
✓
✓
✓
—
—
Manage authority
✓
—
—
—
—
View reports
✓
✓
✓
✓
✓
Four-eyes approval Immutable audit history API scopes Webhook signing Data protection
Visit Security Centre →
RegNexus Books × RegNexus Genesis

Running an FCA-regulated business? You're already in the right place.

RegNexus Books gives you deterministic financial control — and RegNexus Genesis takes you from FCA authorisation to authorised operation. One architecture, from your first application to daily financial truth.

Books + Genesis · built for SPI · API · EMI · SEMI firms
Explore RegNexus for FCA firms →
Pricing

Simple, transparent pricing.

RegNexus Books
£49/mo
Core financial control.
Start
Most popular
RegNexus Books Pro
£149/mo
Advanced intelligence and control.
Start Pro
Enterprise
from £349/mo
Multi-entity, governance, enterprise controls.
Talk to us

All prices + VAT. No introductory discount.

The RegNexus Family

One deterministic architecture. Many surfaces.

Genesis

Build · Authorise · Operate · Grow — FCA authorisation.

Safeguard

Safeguarding governance and control.

Mail

Business communication infrastructure.

Lumen

Run learning at scale.

Request a demo

See RegNexus Books on your numbers.

A 30-minute walkthrough: deterministic ledger, live certification, Horizon forecasting and the AI boundary — mapped to your business.

Know your business.
Test what comes next.

Accounting, forecasting, financial control and decision intelligence — in one deterministic platform.

Start with RegNexus Books Request a demo See it in action →