LedgerCore Documentation

What LedgerCore is

LedgerCore keeps your company's books: invoices you send, bills you receive, what's in the bank, VAT, payroll, and the reports that tell you how the business is doing. It's built on proper double-entry bookkeeping, every number traces back to a journal entry, but you never have to think about that unless you want to.

Two things make it different: it does the typing (upload paperwork and the document pipeline reads, categorises, and drafts entries; overdue invoices get chased automatically; anomalies get flagged overnight), and your data stays on hardware we own, nothing goes to a US cloud.

Try it without signing up

Click Test Drive and you get your own private company, a full set of books to actually use: create invoices, approve bills, reconcile the bank, run the VAT return. It is yours alone and resets itself, so experiment freely; no signup. Prefer to just look around first? Browse a sample company read-only.

Create your account

Start Free with an email, a password, and your company name. The Free plan includes 1 user, 1 company, and 1,000 transactions a month, invoicing, bills, payroll, expenses, banking, reports and VAT returns all included, no card, no time limit. Bank feeds and multi-currency come with paid plans. Your company arrives with a UK chart of accounts and VAT rates already set up.

Your first 15 minutes

1. Add a customer, Contacts → New. Name and email are enough.
2. Send your first invoice, Invoices → New: pick the customer, add a line, save. It starts as a draft, nothing is in your books yet. Approve posts it to the ledger; Send emails it.
3. Record getting paid, Payments → Receive, pick the invoice. The books update themselves.
4. Enter a bill you owe, Bills → New, the purchase-side mirror of an invoice.

Everyday tasks

• Expenses, staff costs and receipts, with an approval flow.
• Products, price-list items so invoice lines fill themselves in.
• Banking, import your statement (CSV), then Reconcile: LedgerCore suggests matches between bank lines and your invoices/bills; you confirm.
• Documents, upload an invoice or receipt under Doc Intelligence and it's read and drafted into the books for your review. The AI drafts; you approve.

Month-end in ten minutes

• Reports, Profit & Loss (am I making money?), Balance Sheet (what do I own and owe?), Trial Balance (for your accountant), Aged Debtors (who owes me, how late?).
• VAT & Tax, the return calculates itself from the books, all nine HMRC boxes. Review, draft, submit when MTD-registered.
• Cash Flow, a forecast with plain-English warnings.

Let it work for you

• Debt Chaser, set the rules once ("polite nudge at 7 days, firmer at 30") and overdue invoices are chased automatically, without double-sending.
• Anomaly Detection, overnight scans flag duplicates, unusual amounts and suspicious patterns as notifications.
• AI Accountant, ask questions about your books in plain English.

Teams, roles, and access

Optional 2FA (TOTP), login lockout with exponential backoff, and SSO (Google, Microsoft, SAML 2.0). Sessions are 15-minute JWTs with rotating 7-day refresh tokens; refresh-token reuse blacklists the chain.

The accounting engine, enforced, not promised

• Schema-per-tenant isolation: every company lives in its own PostgreSQL schema, pinned inside the auth token. One tenant's bug can't read another's data.
• Double-entry enforced at the database: a journal can't post unless debits equal credits, trigger-enforced.
• Posted journals are immutable (corrections by reversal), and the audit trail is append-only and hash-chained with an integrity verifier and CSV/PDF export.
• Fiscal control: closed or locked periods reject postings.
• Money is NUMERIC(19,4) end to end; per-line VAT is rounded then summed, so totals always equal the posted legs.

Automation internals

Events flow through a durable queue (at-least-once, retry with backoff). On top of it:

• Workflow rules per tenant: trigger + conditions + actions (notify, email, update status, create task, emit event), no code needed.
• Scheduled jobs per tenant that never double-run: overdue promotion, debt chase, anomaly scan, cash-flow refresh, VAT-deadline and Companies House checks.
• Debt Chaser: days-overdue rule ladder, templated emails, 7-day per-invoice dedupe, idempotent under event redelivery, and it stands down if your own workflow rule already emails on invoice.overdue.
• Anomaly Detection: Benford's-law analysis, z-score outliers, duplicates, round-number patterns.
• Document pipeline: text PDFs parse locally, scans go through OCR, a parser agent drafts the entry for human approval. AI keys live server-side only.

VAT & HMRC MTD

The return is computed from posted journals, not invoice lists: Box 1 output VAT net of credit notes, Box 4 input VAT net of voids, Boxes 6/7 net sales and purchases with non-VATable categories excluded. Draft, review, submit via HMRC's MTD API once credentials are configured.

Plans

Limits are enforced server-side, not on the honour system.

API access

Everything the UI does goes through /api/v1 and you can too: POST /auth/login for tokens (or httpOnly cookies), GET /auth/me for session introspection, consistent JSON errors with request IDs, per-IP rate limits. The read-only demo doubles as a zero-setup API sandbox.

Self-hosting

LedgerCore is Apache 2.0, run it yourself for nothing. Production is Docker Compose (app, PostgreSQL 16, Redis, S3-compatible attachments, autoheal, backups, optional Prometheus + Grafana monitoring). Shipping is one gated pipeline: typecheck, lint, tests, compose validation, pre-cutover database dump, image build with an instant-rollback tag, smoke checks. Backups run on two independent lanes, and are restore-tested automatically every week, because a backup you've never restored is a hope, not a backup.