{ "name": "Corp Tax Calculator IHT Interest Series", "title": "IHT Interest Series", "url": "https://corptaxcalculator.co.uk/datasets/iht-interest-series/", "csv": "https://corptaxcalculator.co.uk/datasets/iht-interest-series.csv", "markdown": "https://corptaxcalculator.co.uk/datasets/iht-interest-series/index.md", "computed_at": "2026-10-21", "license": "https://corptaxcalculator.co.uk/terms", "headline": "The IHT Interest Series carries 6 published figures read from 2 sources' own pages; the 4 published figures given by rate run from 0.50 to 7.75 percent, read 17 October 2026.", "quotes": [ "The IHT Interest Series carries 6 published figures read from 2 sources' own pages; the 4 published figures given by rate run from 0.50 to 7.75 percent, read 17 October 2026.", "2 of the 7 named sources read in full publish a figure; 5 publish none, read 17 October 2026.", "IHT Interest Series, rate Bank of England Bank Rate: median 3.75 percent across 1 source, read 17 October 2026.", "IHT Interest Series, rate repayment interest minimum floor: median 0.50 percent across 1 source, read 17 October 2026.", "IHT Interest Series, rate late payment interest: median 7.75 percent across 1 source, read 17 October 2026.", "IHT Interest Series, rate repayment interest: median 2.75 percent across 1 source, read 17 October 2026.", "IHT Interest Series, spread over Bank Rate late payment interest, base rate plus: median 4 percent across 1 source, read 17 October 2026.", "IHT Interest Series, spread over Bank Rate repayment interest, base rate minus: median 1 percent across 1 source, read 17 October 2026." ], "citation": "\"Corp Tax Calculator IHT Interest Series\", updated 2026-10-21, https://corptaxcalculator.co.uk/datasets/iht-interest-series/.", "changed_since": null, "national": { "unit": "%", "n": 6, "median": 3.25, "min": 0.5, "max": 7.75, "p25": 0.875, "p75": 4.9375, "mean": 3.2917, "units": { "%": 6 }, "published_sources": 2, "named_sources": 7, "read_sources": 7, "not_published": 5, "published_share": 0.286 }, "by_axis": { "rate": { "Bank of England Bank Rate": { "%": { "n": 1, "median": 3.75, "min": 3.75, "max": 3.75, "p25": 3.75, "p75": 3.75, "mean": 3.75 } }, "repayment interest minimum floor": { "%": { "n": 1, "median": 0.5, "min": 0.5, "max": 0.5, "p25": 0.5, "p75": 0.5, "mean": 0.5 } }, "late payment interest": { "%": { "n": 1, "median": 7.75, "min": 7.75, "max": 7.75, "p25": 7.75, "p75": 7.75, "mean": 7.75 } }, "repayment interest": { "%": { "n": 1, "median": 2.75, "min": 2.75, "max": 2.75, "p25": 2.75, "p75": 2.75, "mean": 2.75 } } }, "spread over Bank Rate": { "late payment interest, base rate plus": { "%": { "n": 1, "median": 4, "min": 4, "max": 4, "p25": 4, "p75": 4, "mean": 4 } }, "repayment interest, base rate minus": { "%": { "n": 1, "median": 1, "min": 1, "max": 1, "p25": 1, "p75": 1, "mean": 1 } } } }, "rows": [ { "source": "Bank of England: the interest rate (Bank Rate)", "url": "https://www.bankofengland.co.uk/monetary-policy/the-interest-rate-bank-rate", "figure": "3.75%", "value": 3.75, "unit": "%", "vat": null, "axis": { "rate": "Bank of England Bank Rate" }, "retrieved_at": "2026-10-16", "quote": "Today, we’ve held Bank Rate at 3.75%.", "source_class": "primary-government", "text_sha256": "daf93bbaf27862b1896df16c013adb9a1ab70d5409995a5b0d47036f5fd3993f" }, { "source": "GOV.UK: rates and allowances - HMRC interest rates for late and early payments", "url": "https://www.gov.uk/government/publications/rates-and-allowances-hmrc-interest-rates-for-late-and-early-payments/rates-and-allowances-hmrc-interest-rates", "figure": "4%", "value": 4, "unit": "%", "vat": null, "axis": { "spread over Bank Rate": "late payment interest, base rate plus" }, "retrieved_at": "2026-10-17", "quote": "late payment interest set at base rate plus 4% from 6 April 2025 (was plus 2.5% on or before 5 April 2025)", "source_class": "primary-government", "text_sha256": "d123618b99b9716a929ea8c274b1b315e3ed47abd3a0093cfa1a138d1febd668" }, { "source": "GOV.UK: rates and allowances - HMRC interest rates for late and early payments", "url": "https://www.gov.uk/government/publications/rates-and-allowances-hmrc-interest-rates-for-late-and-early-payments/rates-and-allowances-hmrc-interest-rates", "figure": "1%", "value": 1, "unit": "%", "vat": null, "axis": { "spread over Bank Rate": "repayment interest, base rate minus" }, "retrieved_at": "2026-10-17", "quote": "repayment interest, set at base rate minus 1%, with a lower limit of 0.5% (known as the ‘minimum floor’)", "source_class": "primary-government", "text_sha256": "d123618b99b9716a929ea8c274b1b315e3ed47abd3a0093cfa1a138d1febd668" }, { "source": "GOV.UK: rates and allowances - HMRC interest rates for late and early payments", "url": "https://www.gov.uk/government/publications/rates-and-allowances-hmrc-interest-rates-for-late-and-early-payments/rates-and-allowances-hmrc-interest-rates", "figure": "0.5%", "value": 0.5, "unit": "%", "vat": null, "axis": { "rate": "repayment interest minimum floor" }, "retrieved_at": "2026-10-17", "quote": "Repayment interest will be paid at 0.5% until the Bank of England raises the base rate above 1.5%.", "source_class": "primary-government", "text_sha256": "d123618b99b9716a929ea8c274b1b315e3ed47abd3a0093cfa1a138d1febd668" }, { "source": "GOV.UK: rates and allowances - HMRC interest rates for late and early payments", "url": "https://www.gov.uk/government/publications/rates-and-allowances-hmrc-interest-rates-for-late-and-early-payments/rates-and-allowances-hmrc-interest-rates", "figure": "7.75%", "value": 7.75, "unit": "%", "vat": null, "axis": { "rate": "late payment interest" }, "retrieved_at": "2026-10-17", "quote": "late payment interest rate — 7.75% from 9 January 2026", "source_class": "primary-government", "text_sha256": "d123618b99b9716a929ea8c274b1b315e3ed47abd3a0093cfa1a138d1febd668" }, { "source": "GOV.UK: rates and allowances - HMRC interest rates for late and early payments", "url": "https://www.gov.uk/government/publications/rates-and-allowances-hmrc-interest-rates-for-late-and-early-payments/rates-and-allowances-hmrc-interest-rates", "figure": "2.75%", "value": 2.75, "unit": "%", "vat": null, "axis": { "rate": "repayment interest" }, "retrieved_at": "2026-10-17", "quote": "repayment interest rate — 2.75% from 9 January 2026", "source_class": "primary-government", "text_sha256": "d123618b99b9716a929ea8c274b1b315e3ed47abd3a0093cfa1a138d1febd668" } ], "not_published": [ { "source": "GOV.UK: HMRC interest rates for late and early payments (publication)", "url": "https://www.gov.uk/government/publications/rates-and-allowances-hmrc-interest-rates-for-late-and-early-payments", "retrieved_at": "2026-10-10", "reason": "read in full and no accepted figure on the page" }, { "source": "GOV.UK: Rates and allowances - Inheritance Tax thresholds and interest rates", "url": "https://www.gov.uk/government/publications/rates-and-allowances-inheritance-tax-thresholds-and-interest-rates", "retrieved_at": "2026-10-10", "reason": "read in full and no accepted figure on the page" }, { "source": "Bank of England Bank Rate database", "url": "https://www.bankofengland.co.uk/boeapps/database/Bank-Rate.asp", "retrieved_at": "2026-10-10", "reason": "read in full and no accepted figure on the page" }, { "source": "IHTA 1984 s.233: interest on unpaid tax", "url": "https://www.legislation.gov.uk/ukpga/1984/51/section/233", "retrieved_at": "2026-10-17", "reason": "read in full and no accepted figure on the page" }, { "source": "GOV.UK: Inheritance Tax payment deadlines", "url": "https://www.gov.uk/paying-inheritance-tax/deadlines", "retrieved_at": "2026-09-12", "reason": "read in full and no accepted figure on the page" } ], "sources": [ { "url": "https://www.gov.uk/government/publications/rates-and-allowances-hmrc-interest-rates-for-late-and-early-payments/rates-and-allowances-hmrc-interest-rates", "label": "GOV.UK: rates and allowances - HMRC interest rates for late and early payments", "license": "the publisher's own terms; quoted for reporting and comment" }, { "url": "https://www.gov.uk/government/publications/rates-and-allowances-hmrc-interest-rates-for-late-and-early-payments", "label": "GOV.UK: HMRC interest rates for late and early payments (publication)", "license": "the publisher's own terms; quoted for reporting and comment" }, { "url": "https://www.gov.uk/government/publications/rates-and-allowances-inheritance-tax-thresholds-and-interest-rates", "label": "GOV.UK: Rates and allowances - Inheritance Tax thresholds and interest rates", "license": "the publisher's own terms; quoted for reporting and comment" }, { "url": "https://www.bankofengland.co.uk/boeapps/database/Bank-Rate.asp", "label": "Bank of England Bank Rate database", "license": "the publisher's own terms; quoted for reporting and comment" }, { "url": "https://www.legislation.gov.uk/ukpga/1984/51/section/233", "label": "IHTA 1984 s.233: interest on unpaid tax", "license": "the publisher's own terms; quoted for reporting and comment" }, { "url": "https://www.gov.uk/paying-inheritance-tax/deadlines", "label": "GOV.UK: Inheritance Tax payment deadlines", "license": "the publisher's own terms; quoted for reporting and comment" }, { "url": "https://www.bankofengland.co.uk/monetary-policy/the-interest-rate-bank-rate", "label": "Bank of England: the interest rate (Bank Rate)", "license": "the publisher's own terms; quoted for reporting and comment" } ], "methodology": "Every row is a verbatim sentence read from the named source's own page through our fetch service on the date shown, hash-pinned to the stored read (the sha of the page's visible text; the raw page is mirrored to R2). 2 of the 7 named sources that could be read published a usable figure; 5 published none and are recorded as not published, never filled in; 0 could not be read (blocked, dead or unreachable) and count nowhere. The headline figures (median, minimum, maximum, quartiles) are over ONE figure per source for each breakdown it prices, in % (a source's median where its page yielded several accepted sentences for one breakdown), so a page that gives figures for several breakdowns gives one for each and N counts 6 figures, never sentences; 29 candidate sentence(s) were refused by a reviewer with the reason recorded. The fuller derivation this dataset is chartered to grow into (not yet what the figures above are; they are each source's own published figure as read): the full dated HMRC IHT interest series joined to the Bank of England Bank Rate on the same dates, so interest over any period between a death and a payment is computed rate-segment by rate-segment rather than at today's rate - which is the only correct way to do it and the reason a single-rate calculator is wrong for every estate open across a change. The published figure is the series itself with each change dated, plus the current rate, the spread over base, and the count of changes in the last five years.", "embed": "

0.50 to 7.75 percent

4 of 6 published figures (rate), IHT Interest Series, across 2 sources, read 17 October 2026

Source: Corp Tax Calculator IHT Interest Series
" }