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Local invoicing and quotes

Offline invoicing, quotes, clients and expenses with CSV/PDF export and local privacy.

Coming soon

Affordable premium, offline-first software. Local-first; no subscription trap. Culltron Max and Ultra X27 (Ultra X27 generation). Affiliate disclosure.

What this covers

Quotes and invoices are the heart of a small business's cash flow. Books Max produces them offline and records them in an append-only ledger, so the history can be trusted.

The Culltron tools for this job

Books Max

Offline invoicing, quotes, clients, products and expenses. Data stays on your machine, and the core tools need no account or internet.

  • Invoices, quotes, client and product lists, and expense records.
  • An accounting core with exact-decimal amounts, a chart of accounts, balanced append-only journals and trial balances.
  • Corrections made only by reversal, so posted records are never overwritten.
  • Ledger-backed customer receipts and credit notes, posted by explicit confirmed actions.
  • A banking reconciliation inbox: import statements, detect duplicates and confirm matches to invoices or expenses.
  • CSV and JSON export of your records.

Limits: Bank and tax-provider connections stay switched off until approved credentials and launch checks are in place. Close workflows cover a single set of books, not a multi-client practice.

PDF Max

A local PDF workstation. Nothing is uploaded unless a separate connected workflow says so explicitly.

  • A viewer with page thumbnails, zoom, rotate, jump, keyboard navigation and text search.
  • Organise, rotate, delete, crop and extract exact page ranges. Merge files, turn images into a PDF, export pages to PNG and extract text.
  • Edit metadata and add watermarks and page numbers.
  • Inspect and fill AcroForm fields, author fields after review, and optionally flatten. Add bookmarks and page labels.
  • Local preflight checks for structure, accessibility and print, plus bounded OCR to create searchable copies.
  • AES-256 password encryption and authorised decryption, available when qpdf is installed. Each change writes a separate copy and a receipt.

Ultra X27: adds stamps, presets for watermarks and page numbers, appearance-only signature marks, metadata cleaning, three lossless optimisation profiles, batch merge/split/watermark/numbering, and document binders.

Limits: Production edits refuse dynamic XFA forms and PDFs that already carry signatures rather than silently invalidating them. Signature marks are visual and are not digital signatures.

Who it is for

How it works

  1. Each Max app is a separate desktop product built on Culltron's shared, hardened platform.
  2. Files and records stay in a local folder on your machine, and the core tools work offline.
  3. A signed licence lease unlocks the paid edition. Ultra X27 adds advanced features that the server enforces.
  4. When you change a file, the app writes a new copy, often with a checksum receipt, instead of silently overwriting your original.

Frequently asked questions

Can a posted invoice be edited?

Corrections are made by reversal, so posted records are never silently overwritten.

Does it handle credit notes and receipts?

Yes, as ledger-backed customer receipts and credit notes posted through explicit confirmed actions.

Does it file tax returns?

No. Tax-provider connections stay switched off until approved.

Can I move to another system later?

Yes. Your records export as CSV and JSON.

Release status: built and tested in the repository. A public download appears only after signing, checksum verification and release approval; see Downloads.