BusCalcTools

Editorial Policy

Last reviewed: 2026-05-12

How we research, write, fact-check, and update the calculators and articles on BusCalcTools.

Sources

Every tax rate, interest-rate benchmark, employer-cost percentage, and industry multiple cited on this site comes from one of these primary sources. Each calculator page lists the sources used for its region-aware defaults, with last-verified dates.

USA

  • IRS — irs.gov
  • US Small Business Administration — sba.gov
  • FRED (St Louis Fed) — fred.stlouisfed.org
  • BLS / Census Bureau for industry benchmarks

United Kingdom

  • HMRC via GOV.UK
  • Bank of England — bankofengland.co.uk
  • ONS — ons.gov.uk
  • BDO / Companies House for industry benchmarks

South Africa

  • SARS — sars.gov.za
  • South African Reserve Bank — resbank.co.za
  • Stats SA — statssa.gov.za

General benchmarks

  • Industry-published multiples (BDO, BVR)
  • Amazon, Etsy, eBay, Shopify seller-fee schedules
  • Reviewed annually against primary publications

Calculation logic

Every calculator uses a hand-written, hand-reviewed calculation. Formulas are listed in the “See the formula” accordion on each calc page and matched against standard accounting or finance textbook definitions. We do not use closed-source third-party calculation libraries for tax or financial maths.

Authorship

All content is written or reviewed by James Blanckenberg. Every blog post carries a visible byline and a “Last reviewed” date.

AI use disclosure

Some article drafts are prepared with AI assistance (Claude). Every AI-drafted article goes through a manual edit pass for accuracy, tone, and fact-checking against primary sources before publication. AI is not used for calculator logic, tax rates, or numerical benchmarks — those are hand-written, sourced, and reviewed.

We don't publish AI-generated content that hasn't been read and corrected by a human.

Update cadence

  • Tax rates are reviewed every 12 months or whenever a region changes its headline rate (typically following a Spring Budget in the UK, the federal budget cycle in the US, or the Medium-Term Budget Policy Statement in South Africa).
  • Interest-rate benchmarks (SBA loan range, UK SME loan range, SA prime + margin) are reviewed quarterly.
  • Articlesare reviewed annually for accuracy. Articles that contain time-sensitive figures (e.g. “UK Freelance Rates by Industry 2026”) are reviewed at year-end.
  • Industry benchmarks (typical margins by sector, valuation multiples) are reviewed when authoritative new data is published.

Corrections

If you spot an error, an out-of-date rate, or a calculation that contradicts your accountant, please tell us: [email protected].

Corrections are made within 7 days of confirmation. Substantive changes are noted with a dated changelog entry on the affected page.

Conflict of interest

We have no affiliate relationships with any bank, lender, accountant, ecommerce platform, or financial product mentioned on the site. See our advertising disclosure for how the site is monetised.