KIkifinance.xyzIncome tax · Made plain
About

Independent tax-bracket reference, reviewed by a working chartered tax adviser.

kifinance.xyz publishes a single calculator with one job: walk income through the official progressive bracket schedules of Ireland, the UK, and the US, with full bracket-by-bracket transparency and a clean separation of income tax from social charges.

Why this site exists

Most consumer tax calculators return a single total and call it a day. The total is correct (often) but it hides the most useful information: how the bracket schedule actually applies to your income, where the marginal rate kicks in, and how social charges (PRSI, USC, National Insurance, FICA) layer on top of the income-tax figure. The transparency matters because most personal financial decisions — pension contributions, salary-sacrifice arrangements, taking a bonus across a tax-year boundary — turn on the marginal rate, not the average rate.

kifinance.xyz publishes the bracket walk explicitly. The schedules are sourced from Revenue (Ireland), HMRC (UK), and the IRS (US), refreshed annually after the relevant tax authority publishes the new year's rates. The calculation engine is a single readable JavaScript file and the math is the same arithmetic the official tax authorities use.

Editorial principles

  • Official sources only. Bracket schedules sourced from Revenue Commissioners, HMRC, and IRS publications. We do not use third-party aggregators.
  • Annual refresh. Schedules refreshed each January after the relevant authority publishes the new tax year's rates.
  • Named accountability. Aisling O'Brien, CTA, is the responsible reviewer. Her CTA membership is verifiable through the Irish Tax Institute public directory.
  • No commercial relationships. The site does not earn referral fees from any tax-preparation service, accounting firm, or financial product.
  • Privacy by architecture. Income figures and deduction inputs stay in your browser.

Verification methodology

  1. Schedule sourcing. Each tax-year refresh begins with the official publication: the Revenue PAYE/USC/PRSI rates table, the HMRC tax rates and allowances bulletin, and the IRS Revenue Procedure listing federal brackets and standard deductions.
  2. Cross-check against official calculators. A fixed test set of 40 input/output pairs is fed through both this site's engine and the official Revenue, HMRC, and IRS public calculators. Every release must match to within €1.
  3. Bracket walk transparency. The bracket-by-bracket breakdown displayed in the tool is generated by the same engine that computes the headline figure — not a separate display routine. The transparency check and the calculation are the same code path.
  4. Refresh date logged. The most recent refresh date is recorded in the engine's source-file header and on the tool's stamp.

The team

kifinance.xyz operates as a one-person editorial project alongside Aisling's tax advisory practice. Aisling reviews every release of the calculator and every page of reference content before publication. She holds final editorial authority and is the named accountable person for every figure on the site.

A part-time research associate based in Cork maintains the schedule refresh pipeline (downloading official rate publications and reformatting them for the bundled tables). The associate is named in the public changelog only when their input has produced a substantive change.

What this site is not

  • Not regulated tax advice. Aisling's CTA membership and BL qualification permit her to give regulated tax advice in her private practice. The site itself, however, is editorial and informational. For specific filing decisions, consult a qualified tax adviser. Verify any Irish CTA via the Irish Tax Institute directory.
  • Not a tax-filing service. The calculator does not file your return, generate official forms, or interface with Revenue/HMRC/IRS systems.
  • Not aware of credits, reliefs, and deductions in detail. The calculator handles standard deductions and a single pre-tax deduction line. It does not model the full range of personal credits (CGT exemptions, rent relief, medical expenses, charitable donations, etc.). For complete personalised analysis, use the official authority calculators or a tax adviser.
  • Not US state-aware. The US figures are federal only. State income tax can add 0–13 % to the total burden depending on jurisdiction.

Get in touch

Calculation queries, schedule discrepancies, content corrections, and partnership enquiries are all handled through the contact page. We commit to acknowledging every well-formed message within 24 business hours.