The British system, end to end
UK chart of accounts, UK GAAP and FRS 105 for micro-entities, HMRC VAT, Companies House, PAYE and UK employment law.
Business managementWeb (admin console)V1.0Available now
Deal
All the management of a British company, in a single console.
Deal is Dealmood & Solutions LTD's in-house management module: sealed double-entry bookkeeping, invoices, VAT, management accounts, annual accounts, contracts drafted with the help of AI, staff and payroll. Everything follows the British system: UK GAAP (FRS 105), HMRC, Companies House and UK employment law.
Operational and used in-house by Dealmood & Solutions LTD for its day-to-day management.
British systemSealed journalAdministrators only
The concept
A limited company's books, kept to British standards
A company under English law must keep reliable records, file its VAT with HMRC and deliver its accounts to Companies House. Deal brings all of this together in a console reserved for administrators, with registers nobody can rewrite.
A journal that cannot be rewritten
Each entry is chained to the previous one by a SHA-256 hash; no changes or deletions, even directly in the database.
Documents ready to sign
Invoices, management accounts and annual accounts come out as signed and stamped PDFs, each with a verifiable unique ID.
In service at Dealmood & Solutions LTD
Private company limited by shares, registered in England & Wales under number 17553096, registered office: 167-169 Great Portland Street, 5th Floor, London W1W 5PF. Deal keeps its books, issues its invoices and prepares its statutory obligations every day.
Deal in action
From invoice to filed accounts, with nothing keyed in twice
An issued invoice follows its whole path through Deal: it goes into the journal, feeds the VAT, enters the month's closing, then the management accounts and the annual accounts. Hover over the animation to pause it, or pick a step.
Step 1 of 6 : The invoice is issued. Numbered with no gaps, as a bilingual French and English PDF, signed and stamped.
In pictures
The console, as it is
Features
Sell, buy, keep the books, and account for it all
Accounting
- UK chart of accounts, double-entry journal sealed with SHA-256
- General ledger, trial balance, profit and loss account and balance sheet in UK format
- Monthly closing sealed in order, year-end close
- Monthly, quarterly, half-yearly and annual accounts in one click, compared with the previous period
Annual accounts and Companies House
- Bilingual directors' copy
- Companies House filing copy: in English, black on white, micro-entity balance sheet, section 475 to 477 statements and the director's signature on the balance sheet page, with no profit and loss account (section 444)
- Statutory calendar: annual accounts, confirmation statement, Corporation Tax and CT600, with links to GOV.UK
- Deal never files on your behalf: it prepares the documents and records the filing reference
VAT
- UK VAT codes on every line
- 9-box HMRC Making Tax Digital return
- Locking of the period filed
Sales
- Quotes, invoices, credit notes and reminders
- Late payment interest under the Late Payment Act 1998
- Multiple currencies, bilingual French and English PDFs with the company stamp
Purchases
- Expenses with a mandatory receipt photo, encrypted
- Subcontracting, outsourcing and white label
- Margin tracking per client project
People and payroll
- Hiring generates the contract suited to the status, with a staff number
- PAYE 2026/27 payroll: income tax, employee and employer National Insurance, auto-enrolment pension
- Staff costs per staff number for the year-end
AI-assisted contracts
Statutory clauses, each with its source
Each contract template is linked to the official UK pages that set its rules (GOV.UK, legislation.gov.uk, Acas, ICO). Deal reads them, then Claude, Anthropic's AI, drafts the mandatory clauses for each profile, citing the source of every one. No personal data is ever sent to the AI.
- Employment contract
- Internship
- Freelance and IR35
- Client
- Supplier
- Confidentiality (NDA)
- Partnership
- Subcontracting
- White label
- Outsourcing
Security
Registers that cannot be rewritten, even in the database
Administrators only
Access via JWT and the Admin role; the console locks after 15 minutes of inactivity.
AES-256-GCM encryption
Sensitive fields and receipts are encrypted one by one.
SHA-256 hash chain
Each entry seals the previous one; an integrity check runs through the whole journal.
Append-only registers
PostgreSQL triggers reject any change or deletion, even outside the application.
Sealed, verifiable documents
Each document gets a unique ID sealed with HMAC, recorded in a verifiable registry.
Full audit trail
Every action is logged with its author, date and IP address.
Technology & architecture
Under the hood of Deal
A .NET 10 API in Clean Architecture (Domain, Application, Infrastructure, API) with its own PostgreSQL schema, and an Angular console reserved for administrators. The accounting registers are append-only, guaranteed by PostgreSQL triggers and a SHA-256 hash chain, and every document produced is sealed and verifiable.
- 01
Console
- Angular 21Administration console built with signals and OnPush, in French, English, German and Italian
- AccessJWT and Admin role, locked after 15 minutes of inactivity
- 02
Deal API
.NET 10 · Clean Architecture
- APIAdministrator endpoints, audit trail with IP address
- ApplicationSales, purchases, journal, VAT, closings, contracts, payroll, statutory obligations
- DomainUK GAAP (FRS 105) rules, HMRC VAT, PAYE 2026/27, with no technical dependency
- 03
Infrastructure
- PostgreSQLEF Core 10, dedicated “deal” schema, append-only triggers
- QuestPDFSigned and stamped PDFs, embedded Outfit fonts, sealed unique ID
- Claude (Anthropic)Official C# SDK: clauses drafted from the official sources, with no personal data
The journey of an invoice
- 1The invoice is issued: its number is assigned and its bilingual PDF is generated, signed and stamped.
- 2The double-entry posting goes into the journal and is chained to the previous one by a SHA-256 hash.
- 3PostgreSQL rejects any change to or deletion of the entry, even with direct database access.
- 4The VAT feeds the 9-box HMRC return; the period filed is then locked.
- 5The month is closed in order and sealed; the management accounts come out as a signed and stamped PDF.
Architecture choices
- A chained journalEach entry carries the SHA-256 hash of the previous one: the slightest tampering breaks the chain and shows up on verification.
- Append-only, enforced by the databasePostgreSQL triggers forbid changing or deleting the registers: corrections are made with a reversing entry.
- Encrypted field by fieldSensitive data (identifiers, bank details, receipts) is encrypted with AES-256-GCM.
- Verifiable documentsEach PDF gets a unique ID sealed with HMAC and recorded in a registry: its authenticity can be proven.
Every technology, by family
Backend
- .NET 10
- C#
- ASP.NET Core
- Clean Architecture
- Entity Framework Core 10
Front-end
- Angular 21
- TypeScript
- Signals
- OnPush
- Tailwind CSS
- i18n fr, en, de, it
Data & storage
- PostgreSQL
- Npgsql
- Dedicated “deal” schema
- Append-only triggers
Artificial intelligence
- Claude (Anthropic)
- Anthropic C# SDK
- GOV.UK, legislation.gov.uk, Acas, ICO
Payments & third-party services
- QuestPDF
- Embedded Outfit fonts
- Anthropic API
Authentication & security
- JWT
- Admin role
- AES-256-GCM
- HMAC
- SHA-256 chain
- Audit log
Quality & tooling
- xUnit
- Testcontainers
- Integration tests on real PostgreSQL
Inventory taken from the product's source code and configuration.
Frequently asked questions
All about Deal
Yes. Deal is operational and used in-house by Dealmood & Solutions LTD to keep its books, issue its invoices, and prepare its VAT and its obligations to HMRC and Companies House.
Would you like us to implement your own accounting solution in your business?
Sealed ledger, invoices and VAT, management accounts, AI-assisted contracts, payroll: we build a bespoke solution for you, following the British system or adapted to the rules of your country. Get in touch to talk it through.