Privacy · 28 September 2026

Security Audit Report — 28 September 2026

Weekly SpeyBooks Security Test Harness report. Grade: A (93%). 18/22 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 21 September 2026

Security Audit Report — 21 September 2026

Weekly SpeyBooks Security Test Harness report. Grade: A (93%). 18/22 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 14 September 2026

Security Audit Report — 14 September 2026

Weekly SpeyBooks Security Test Harness report. Grade: A (93%). 18/22 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 7 September 2026

Security Audit Report — 7 September 2026

Weekly SpeyBooks Security Test Harness report. Grade: A (93%). 18/22 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 31 August 2026

Security Audit Report — 31 August 2026

Weekly SpeyBooks Security Test Harness report. Grade: A (93%). 18/22 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 24 August 2026

Security Audit Report — 24 August 2026

Weekly SpeyBooks Security Test Harness report. Grade: A (93%). 18/22 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 17 August 2026

Security Audit Report — 17 August 2026

Weekly SpeyBooks Security Test Harness report. Grade: A (94%). 19/22 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 10 August 2026

Security Audit Report — 10 August 2026

Weekly SpeyBooks Security Test Harness report. Grade: A (94%). 19/22 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 3 August 2026

Security Audit Report — 3 August 2026

Weekly SpeyBooks Security Test Harness report. Grade: A (94%). 19/22 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 27 July 2026

Security Audit Report — 27 July 2026

Weekly SpeyBooks Security Test Harness report. Grade: A+ (95%). 20/22 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 20 July 2026

Security Audit Report — 20 July 2026

Weekly SpeyBooks Security Test Harness report. Grade: A+ (97%). 21/22 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 13 July 2026

Security Audit Report — 13 July 2026

Weekly SpeyBooks Security Test Harness report. Grade: A+ (100%). 22/22 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 6 July 2026

Security Audit Report — 6 July 2026

Weekly SpeyBooks Security Test Harness report. Grade: A+ (97%). 21/22 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 29 June 2026

Security Audit Report — 29 June 2026

Weekly SpeyBooks Security Test Harness report. Grade: A+ (100%). 22/22 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 22 June 2026

Security Audit Report — 22 June 2026

Weekly SpeyBooks Security Test Harness report. Grade: C (80%). 17/22 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 15 June 2026

Security Audit Report — 15 June 2026

Weekly SpeyBooks Security Test Harness report. Grade: C (92%). 21/22 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 10 June 2026

Security Audit Report — 10 June 2026

Weekly SpeyBooks Security Test Harness report. Grade: A+ (98%). 21/22 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 9 June 2026

Security Audit Report — 9 June 2026

Weekly SpeyBooks Security Test Harness report. Grade: A+ (100%). 22/22 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 8 June 2026

Security Audit Report — 8 June 2026

Weekly SpeyBooks Security Test Harness report. Grade: D (92%). 20/21 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 6 June 2026

Security Audit Report — 6 June 2026

Weekly SpeyBooks Security Test Harness report. Grade: A (100%). 21/21 modules passing. Automated infrastructure security audit.

3 min read →

Privacy · 5 June 2026

Security Audit Report — 5 June 2026

Weekly SpeyBooks Security Test Harness report. Grade: A (100%). 21/21 modules passing. Automated infrastructure security audit.

3 min read →

Philosophy · 1 March 2026

Why Your Accounting Software Shouldn't Need a UI

The dashboard is a crutch. If your accounting software can't be scripted, piped, or automated, it's holding you back. A case for API-first accounting.

4 min read →

Technical · 27 February 2026

Building Idempotent Financial APIs

Network timeouts happen. Retries must be safe. Here's how to implement idempotency keys for financial APIs so duplicate requests produce the same result.

4 min read →

Privacy · 25 February 2026

Why We Don't Connect to Your Bank

Open Banking is convenient. It also gives third parties persistent access to your financial data. SpeyBooks takes a different approach.

5 min read →

Compliance · 23 February 2026

VAT Schemes Explained (With Code)

Standard, Flat Rate, and Cash Accounting — how each UK VAT scheme works, when to use it, and how to implement the calculations in code.

5 min read →

Technical · 21 February 2026

Designing an Accounting API: Lessons Learned

Prefixed IDs, minor units, idempotency keys, and consistent error handling. The design decisions behind the SpeyBooks API and why they matter.

4 min read →

Compliance · 19 February 2026

MTD for Developers: A Technical Guide

Making Tax Digital demystified for developers. OAuth flows, the 9-box VAT return, HMRC's API sandbox, and what your software actually needs to submit.

5 min read →

Privacy · 17 February 2026

Zero Cookies: Building SpeyBooks Without Tracking

No Google Analytics. No tracking pixels. No cookie banner. Here's the technical architecture behind SpeyBooks' zero-tracking approach.

4 min read →

Technical · 15 February 2026

Why We Store Money in Pence (And You Should Too)

Floating-point arithmetic loses money. Integers don't. Here's why SpeyBooks stores every amount in pence and how to do it in your own systems.

3 min read →

Technical · 13 February 2026

Double-Entry Bookkeeping for Developers

Double-entry bookkeeping is a distributed consensus mechanism. Every transaction is a commit that must balance. Here's how it works in code.

3 min read →

Privacy · 13 February 2026

Security Report — February 2026

Monthly automated security assessment of SpeyBooks infrastructure. Grade: A (97%).

2 min read →

Privacy · 13 February 2026

Security Report — February 2026

Monthly automated security assessment of SpeyBooks infrastructure. Grade: A (100%).

2 min read →

Privacy · 13 February 2026

Security Report — February 2026

Monthly automated security assessment of SpeyBooks infrastructure. Grade: A (97%).

2 min read →

Privacy · 13 February 2026

Security Report — February 2026

Monthly automated security assessment of SpeyBooks infrastructure. Grade: A (96%).

2 min read →

Technical · 9 February 2026

Row Level Security: Why Your Data Can't Leak

We shipped PostgreSQL RLS across 25 tables. Here's what it means for your data, how it works, and the bugs we found along the way.

6 min read →

Philosophy · 6 February 2026

What is Accounting as Code?

Accounting belongs in your codebase, not behind a dashboard. A manifesto for developers who treat financial data like any other API.

4 min read →

Accounting as Code Insights

Security Audit Report — 5 October 2026

Security Audit Report — 28 September 2026

Security Audit Report — 21 September 2026

Security Audit Report — 14 September 2026

Security Audit Report — 7 September 2026

Security Audit Report — 31 August 2026

Security Audit Report — 24 August 2026

Security Audit Report — 17 August 2026

Security Audit Report — 10 August 2026

Security Audit Report — 3 August 2026

Security Audit Report — 27 July 2026

Security Audit Report — 20 July 2026

Security Audit Report — 13 July 2026

Security Audit Report — 6 July 2026

Security Audit Report — 29 June 2026

Security Audit Report — 22 June 2026

Security Audit Report — 15 June 2026

Security Audit Report — 10 June 2026

Security Audit Report — 9 June 2026

Security Audit Report — 8 June 2026

Security Audit Report — 6 June 2026

Security Audit Report — 5 June 2026

Why Your Accounting Software Shouldn't Need a UI

Building Idempotent Financial APIs

Why We Don't Connect to Your Bank

VAT Schemes Explained (With Code)

Designing an Accounting API: Lessons Learned

MTD for Developers: A Technical Guide

Zero Cookies: Building SpeyBooks Without Tracking

Why We Store Money in Pence (And You Should Too)

Double-Entry Bookkeeping for Developers

Security Report — February 2026

Security Report — February 2026

Security Report — February 2026

Security Report — February 2026

Row Level Security: Why Your Data Can't Leak

What is Accounting as Code?

Try it yourself