Data Sources and References
Where a WhatsUK calculator applies a published rate, threshold or fee, this is the register it comes from. Each entry names the publisher, the exact page, what it supports, the jurisdiction it applies to and the period it covers.
40 sources from 13 publishers. 11 carry a recorded check date; the rest are shown without one rather than with a borrowed date.
Our Data Source Policy
For statutory figures we use the publication of the body that sets the figure, not financial media, rate aggregators or community-contributed lists. Each source is recorded once in a single register and bound to the specific result or table it supports on each page, so a source that backs one number is not silently treated as backing the rest of the page.
Not every calculator uses a source. 24 of our calculators run a formula on the figures you enter, such as a mortgage repayment or a compound growth projection, where the interest or growth rate is your own assumption. Those pages name the model instead, described under calculation methods. We do not attach a government source to a page that does not use one.
About the check dates. A date in the "Last checked" column means someone opened that page and compared it with the values we hold, for that source's scope only. It is not a statement that every output on every calculator was independently verified on that day, and it is not a professional review. Where no check has been recorded, the column says so. We do not fill the gap with the build date or with another source's date.
Statutory figures shown below apply to the 2026/27 UK tax year (6 April 2026 to 5 April 2027) unless the entry states another period.
Source Register
40 sources across 13 publishers
| Publisher | Source | What it supports | Applies to | Period | Last checked | Link |
|---|---|---|---|---|---|---|
| Child Maintenance Service | GOV.UK how child maintenance is worked out | The gross income rate bands, child-count percentages and shared care reductions | United Kingdom | Current statutory scheme | Not recorded | Open |
| Financial Conduct Authority | FCA motor finance complaints information | The complaint route and current status of the motor finance commission review | United Kingdom | Ongoing review | Not recorded | Open |
| GOV.UK | GOV.UK Child Benefit rates | Weekly Child Benefit for the eldest and each additional child | United Kingdom | 2026/27 tax year | Not recorded | Open |
| GOV.UK | GOV.UK Council Tax discounts and exemptions | Valuation bands, the single person discount, disregards and property exemptions | England | Current scheme rules | Not recorded | Open |
| GOV.UK | GOV.UK ISA allowance | The annual ISA subscription limit and account types | United Kingdom | 2026/27 tax year | Not recorded | Open |
| GOV.UK | GOV.UK National Minimum and Living Wage rates | Age-banded hourly minimum wage rates | United Kingdom | From April 2026 | Not recorded | Open |
| GOV.UK | GOV.UK statutory holiday entitlement | The 5.6 week statutory minimum and how it is pro-rated for part-time work | United Kingdom | Current statutory entitlement | Not recorded | Open |
| GOV.UK | GOV.UK statutory redundancy pay | Age-banded weeks per year of service, the weekly pay cap and the 20 year service cap | England and Wales | 2026/27 statutory rates | Not recorded | Open |
| GOV.UK | GOV.UK workplace pension contributions | Minimum auto-enrolment contribution percentages and the qualifying earnings band | United Kingdom | From April 2019, unchanged for 2026/27 | Not recorded | Open |
| GOV.UK / Student Loans Company | Student loan repayment thresholds | Plan 1, 2, 4, 5 and Postgraduate Loan annual thresholds and the 9% / 6% deduction rates | United Kingdom | 2026/27 tax year | Open | |
| HM Land Registry | HM Land Registry registration fees | Scale 1 and Scale 2 registration fee bands and the reduced fee for electronic applications | England and Wales | Fee Order in force | Not recorded | Open |
| HM Revenue & Customs | HMRC additional property SDLT surcharge | The higher rates for additional dwellings | England and Northern Ireland | From 1 April 2026 | Open | |
| HM Revenue & Customs | HMRC Capital Gains Tax rates | The annual exempt amount and the basic and higher CGT rates | United Kingdom | 2026/27 tax year | Open | |
| HM Revenue & Customs | HMRC company car appropriate percentages | Benefit-in-kind percentages by CO2 emissions and plug-in hybrid electric range | United Kingdom | 2026/27 tax year | Not recorded | Open |
| HM Revenue & Customs | HMRC Construction Industry Scheme deductions | The 0%, 20% and 30% CIS deduction rates and what counts as a qualifying material cost | United Kingdom | Current scheme rules | Not recorded | Open |
| HM Revenue & Customs | HMRC Corporation Tax rates | Small profits rate, main rate, the marginal relief limits and the 3/200 fraction | United Kingdom | Financial year 2026 | Open | |
| HM Revenue & Customs | HMRC Employment Allowance | The employer NI Employment Allowance and its eligibility conditions | United Kingdom | 2026/27 tax year | Not recorded | Open |
| HM Revenue & Customs | HMRC High Income Child Benefit Charge | The adjusted net income taper range and the charge calculation | United Kingdom | 2026/27 tax year | Not recorded | Open |
| HM Revenue & Customs | HMRC Income Tax rates and allowances | Personal allowance, basic, higher and additional rate bands, and the allowance taper | England and Wales | 2026/27 tax year | Open | |
| HM Revenue & Customs | HMRC Inheritance Tax thresholds | The nil-rate band, residence nil-rate band, taper and the 40% rate | United Kingdom | 2026/27 tax year | Not recorded | Open |
| HM Revenue & Customs | HMRC Marriage Allowance | The transferable allowance amount, eligibility conditions and backdating window | United Kingdom | 2026/27 tax year | Not recorded | Open |
| HM Revenue & Customs | HMRC National Insurance rates and categories | Class 1 employee and employer rates, primary and secondary thresholds, and the upper earnings limit | United Kingdom | 2026/27 tax year | Open | |
| HM Revenue & Customs | HMRC off-payroll working (IR35) | The deemed employment payment calculation and the 5% allowance rules | United Kingdom | Current guidance | Not recorded | Open |
| HM Revenue & Customs | HMRC pension annual allowance | The annual allowance, tapering and carry-forward rules | United Kingdom | 2026/27 tax year | Not recorded | Open |
| HM Revenue & Customs | HMRC salary sacrifice and PAYE | How a sacrificed amount reduces gross pay for income tax and National Insurance | United Kingdom | Current guidance | Not recorded | Open |
| HM Revenue & Customs | HMRC Self Assessment | Filing deadlines, payments on account and the Class 4 NI treatment of self-employed profits | United Kingdom | 2026/27 tax year | Not recorded | Open |
| HM Revenue & Customs | HMRC Stamp Duty Land Tax residential rates | SDLT band thresholds and first-time buyer relief | England and Northern Ireland | From 1 April 2026 | Open | |
| HM Revenue & Customs | HMRC tax on dividends | The dividend allowance and the ordinary, upper and additional dividend rates | United Kingdom | 2026/27 tax year | Open | |
| HM Revenue & Customs | HMRC tax on rental income | How rental profit is taxed and the finance cost restriction for individual landlords | United Kingdom | 2026/27 tax year | Not recorded | Open |
| HM Revenue & Customs | HMRC VAT invoice requirements | The fields a valid VAT invoice must contain | United Kingdom | Current guidance | Not recorded | Open |
| HM Revenue & Customs | HMRC VAT rates | Standard, reduced and zero VAT rates | United Kingdom | Current rates | Open | |
| HM Revenue & Customs | HMRC VAT registration threshold | The compulsory registration and deregistration turnover thresholds | United Kingdom | 2026/27 | Open | |
| NHS | NHS body mass index guidance | The BMI formula and the NHS weight category ranges | United Kingdom | Current NHS guidance | Not recorded | Open |
| NHS Business Services Authority | NHSBSA member contribution tiers | Actual pensionable pay tier thresholds and the contribution rate for each tier | England and Wales | 2025/26 and 2026/27 scheme years | Not recorded | Open |
| NHS Employers | NHS Employers Agenda for Change pay scales | Band and pay point salaries and the High Cost Area Supplement bounds | England | 2026/27 pay year | Not recorded | Open |
| NHS Employers | NHS Terms and Conditions of Service Handbook | Agenda for Change annual leave entitlement by length of service and general public holidays | England | Current handbook | Not recorded | Open |
| Office for National Statistics | ONS Consumer Price Index | The published CPI series used to restate amounts in real terms | United Kingdom | Published series | Not recorded | Open |
| Ofgem | Ofgem energy price cap | The capped unit rates and standing charges used as the default tariff assumption | England and Wales | Current cap period | Not recorded | Open |
| Scottish Government | Scottish Income Tax rates and bands | The six Scottish rate bands applied to earned and pension income | Scotland | 2026/27 tax year | Open | |
| Valuation Office Agency | VOA Council Tax bands | Band valuation dates and the statutory band proportions relative to Band D | England and Wales | Current band structure | Not recorded | Open |
GOV.UK how child maintenance is worked out
The gross income rate bands, child-count percentages and shared care reductions
FCA motor finance complaints information
The complaint route and current status of the motor finance commission review
GOV.UK Child Benefit rates
Weekly Child Benefit for the eldest and each additional child
GOV.UK Council Tax discounts and exemptions
Valuation bands, the single person discount, disregards and property exemptions
GOV.UK ISA allowance
The annual ISA subscription limit and account types
GOV.UK National Minimum and Living Wage rates
Age-banded hourly minimum wage rates
GOV.UK statutory holiday entitlement
The 5.6 week statutory minimum and how it is pro-rated for part-time work
GOV.UK statutory redundancy pay
Age-banded weeks per year of service, the weekly pay cap and the 20 year service cap
GOV.UK workplace pension contributions
Minimum auto-enrolment contribution percentages and the qualifying earnings band
Student loan repayment thresholds
Plan 1, 2, 4, 5 and Postgraduate Loan annual thresholds and the 9% / 6% deduction rates
HM Land Registry registration fees
Scale 1 and Scale 2 registration fee bands and the reduced fee for electronic applications
HMRC additional property SDLT surcharge
The higher rates for additional dwellings
HMRC Capital Gains Tax rates
The annual exempt amount and the basic and higher CGT rates
HMRC company car appropriate percentages
Benefit-in-kind percentages by CO2 emissions and plug-in hybrid electric range
HMRC Construction Industry Scheme deductions
The 0%, 20% and 30% CIS deduction rates and what counts as a qualifying material cost
HMRC Corporation Tax rates
Small profits rate, main rate, the marginal relief limits and the 3/200 fraction
HMRC Employment Allowance
The employer NI Employment Allowance and its eligibility conditions
HMRC High Income Child Benefit Charge
The adjusted net income taper range and the charge calculation
HMRC Income Tax rates and allowances
Personal allowance, basic, higher and additional rate bands, and the allowance taper
HMRC Inheritance Tax thresholds
The nil-rate band, residence nil-rate band, taper and the 40% rate
HMRC Marriage Allowance
The transferable allowance amount, eligibility conditions and backdating window
HMRC National Insurance rates and categories
Class 1 employee and employer rates, primary and secondary thresholds, and the upper earnings limit
HMRC off-payroll working (IR35)
The deemed employment payment calculation and the 5% allowance rules
HMRC pension annual allowance
The annual allowance, tapering and carry-forward rules
HMRC salary sacrifice and PAYE
How a sacrificed amount reduces gross pay for income tax and National Insurance
HMRC Self Assessment
Filing deadlines, payments on account and the Class 4 NI treatment of self-employed profits
HMRC Stamp Duty Land Tax residential rates
SDLT band thresholds and first-time buyer relief
HMRC tax on dividends
The dividend allowance and the ordinary, upper and additional dividend rates
HMRC tax on rental income
How rental profit is taxed and the finance cost restriction for individual landlords
HMRC VAT invoice requirements
The fields a valid VAT invoice must contain
HMRC VAT registration threshold
The compulsory registration and deregistration turnover thresholds
NHS body mass index guidance
The BMI formula and the NHS weight category ranges
NHSBSA member contribution tiers
Actual pensionable pay tier thresholds and the contribution rate for each tier
NHS Employers Agenda for Change pay scales
Band and pay point salaries and the High Cost Area Supplement bounds
NHS Terms and Conditions of Service Handbook
Agenda for Change annual leave entitlement by length of service and general public holidays
ONS Consumer Price Index
The published CPI series used to restate amounts in real terms
Ofgem energy price cap
The capped unit rates and standing charges used as the default tariff assumption
Scottish Income Tax rates and bands
The six Scottish rate bands applied to earned and pension income
Figures held for 2026/27
These are the values currently in the shared tax config, taken from the sources above. They were last compared with GOV.UK on . Figures used by calculators but not listed here, such as scheme-specific pay or contribution tables, carry their own source in the register and no check date is claimed for them.
Income tax
Personal allowance £12,570, basic rate 20% to £50,270, higher rate 40% to £125,140, additional rate 45% above that, allowance tapered by £1 for every £2 above £100,000.
Scottish income tax
Starter 19% to £16,537, basic 20% to £29,526, intermediate 21% to £43,662, higher 42% to £75,000, advanced 45% to £125,140, top 48% above £125,140.
National Insurance
Employee 8% and 2%, employer 15% above the secondary threshold £5,000, primary threshold £12,570, upper earnings limit £50,270, Employment Allowance £10,500 for eligible employers.
Corporation tax
Small profits rate 19% up to £50,000, main rate 25% above £250,000, marginal relief fraction 3/200 in between.
Capital Gains Tax
Basic rate 18%, higher rate 24%, annual exempt amount £3,000.
Stamp Duty Land Tax
Standard bands, first-time buyer relief 0% up to £300,000 and 5% to £500,000 with no relief above £500,000, additional dwellings surcharge 5%.
VAT
Standard 20%, reduced 5%, registration threshold £90,000, deregistration threshold £88,000.
How this register is maintained
The register is a single data file in the site's source code, so a change to it is version-controlled and appears in the page above on the next publish. Adding a source requires the publisher, the exact URL, what it supports, the jurisdiction and the period it covers. A check date is optional and is only added when a check actually happened.
Rates are revisited when a Budget or a new tax year changes something we hold, and when a reader reports a figure that does not match. There is no automated feed monitoring and no fixed turnaround time we can guarantee, so we do not publish one. What we can say is that the shared tax config is one file, so a confirmed rate change reaches every calculator that uses it in a single edit.
If a source or rate here looks wrong or out of date, please contact us with the page and the figure. Confirmed numeric corrections are logged on the updates page with the date they were applied.
About this register
This register is maintained by James Hartley, founder of WhatsUK. Alongside it, 13 calculation methods are documented on the methodology page for the tools that run a model rather than apply a published rate. If you believe a source is out of date or we have missed an official publication, please contact us.