Reference

Methodology and changelog

Established Finance publishes three datasets and twelve calculators and checkers of its own. This page explains how each one is put together, where its figures come from, how dates and versions work, and what happens when something turns out to be wrong. The changelog at the bottom lists every material correction so far. Editorial standards covers the checks every page goes through, and data sources lists the outside sources the site cites.

Read the editorial standards

What this page covers

Three datasets and twelve tools are built here, not cited

Most figures on Established Finance come from someone else: HMRC, Companies House, legislation.gov.uk. Those are listed on data sources. The datasets and tools below are different. We compiled the datasets and wrote the tools, so their accuracy is our problem, and how they're built has to be written down somewhere you can check it.

Asset	What it is	Where its figures come from	Last updated
R&D rule timeline	Dataset, 7 dated entries	gov.uk, legislation.gov.uk and HMRC manual pages, one source per entry	24 September 2026
R&D adviser register	Dataset, 17 firms: 16 vetted, 1 queued	Each firm's own website, Companies House and HMRC's AML supervised business register	15 September 2026
R&D tribunal case tracker	Dataset, 11 First-tier Tribunal decisions	Published tribunal decisions where freely available, cross-checked against independent professional reports	15 September 2026
Prescribed part calculator	Calculator	A formula fixed in legislation	22 September 2026
Borrowing base calculator	Calculator	Your figures, and advance rates you can change	22 September 2026
Charge priority waterfall	Calculator	The statutory order of payment in a liquidation, applied to your figures	23 September 2026
Company size checker	Calculator	Thresholds fixed in the Companies Act 2006, applied to your figures	23 September 2026
Retention release estimator	Calculator	Your contract's retention terms, with HMRC's CIS rates applied at the date of release	23 September 2026
Duty deferment guarantee estimator	Calculator	HMRC's guarantee waiver and CCG rules, applied to your busiest month and balance sheet	23 September 2026
Facility switch cost estimator	Calculator	Your agreements and quotes, with Companies House's charge registration fee	24 September 2026
Facility eligibility checker	Routing checker	Our own routing, no figures	15 September 2026
R&D notification deadline checker	Date checker	HMRC's notification window and three-year exemption, applied to your dates	15 September 2026
R&D scheme checker	Rules checker	HMRC's scheme start dates and the ERIS intensity threshold, applied to your answers	15 September 2026
R&D claim value estimator	Calculator	HMRC's merged scheme and ERIS rates, payment steps and PAYE cap, with Corporation Tax rates, applied to your figures	23 September 2026
R&D enquiry risk score	Risk checker	HMRC's random enquiry findings and its GfC3 compliance guidance, scored by our own stated rule	23 September 2026

"Last updated" is the date of the last logged change to the page or the data it shows, from the same record that dates every page on the site. It isn't a review date.

The datasets

How the three R&D datasets are compiled

All three were compiled by checking each entry individually against its sources, not scraped in bulk. Each one sits in a single data file that the web page reads directly, so the page and the data can't disagree. Where a detail couldn't be confirmed from a primary source, the field is left empty and the entry says why. We don't fill gaps with a best guess.

R&D rule timeline

An entry goes in only once the change is confirmed against gov.uk, legislation.gov.uk or an HMRC manual page. Commentary from advisers and the trade press isn't enough on its own. Past events are never deleted, because the timeline's job is to show what changed and when. Every entry names its source and the date it was checked. Current entries were checked on 9 August 2026 and 15 September 2026.

R&D adviser register

Each firm was checked against its own website, Companies House and, where it could be done, HMRC's public AML supervised business register. "Vetted" means that check is complete and the entry says what the firm does and doesn't disclose, gaps included. "Queued" means a core fact, usually the firm's legal identity, is still unresolved. Being listed isn't an endorsement, and it doesn't mean the firm has any introducer or commercial relationship with us.

All 17 firms were last checked on 9 August 2026. The register deliberately doesn't mark any firm as registered or unregistered under HMRC's new tax adviser registration rules, because no public lookup exists to check that, for us or for you. The register page sets out why.

R&D tribunal case tracker

Where the full decision is freely available, each case was checked against it: on BAILII or the National Archives, or in 2 cases a copy of the decision hosted by a tax adviser. For 3 cases we couldn't find the full decision on a free public site, so those entries rest on professional case notes and their source label says so. Every case was also cross-checked against at least one independent professional report, and cases that couldn't be corroborated were left out. The scheme each claim was made under is inferred from the accounting period in the decision, because older cases are often cited as if they settle questions under the current merged scheme when they don't. Where a detail such as a hand-down date couldn't be confirmed, it's left blank rather than estimated.

The tracker is a researched set of past decisions, not a live feed. New decisions aren't added automatically. Its journalist pack has every case in one table and the data as CSV and JSON.

Versions and DOIs

The DOI copy is a snapshot. The web page is the current version.

Each dataset has a DOI through Zenodo and is licensed CC BY 4.0, so it can be cited and reused with attribution. The files deposited on Zenodo on 14 September 2026 are a snapshot of the data at that point. The corrections dated 15 September 2026 in the changelog below are on this site but not yet in a new Zenodo version. Until one is deposited, cite the DOI and check this changelog for anything corrected since.

Dataset	DOI	Zenodo record
R&D rule timeline	10.5281/zenodo.22753341	zenodo.org
R&D adviser register	10.5281/zenodo.22753343	zenodo.org
R&D tribunal case tracker	10.5281/zenodo.22753345	zenodo.org

The calculators and checkers

What each tool works out, and what it leaves to you

Every tool runs in your browser. Nothing you type is saved or sent. The seven calculators also show worked examples and a results table as plain page content, so they still make sense without JavaScript, and the figures in each example can be checked by hand.

Prescribed part calculator

Works out: The share of a company's net property set aside for unsecured creditors under section 176A of the Insolvency Act 1986.
Method: 50% of the first £10,000 of net property plus 20% of the rest (Prescribed Part Order 2003, article 3), capped at £800,000. The older £600,000 cap still applies where the net property goes to a floating charge created before 6 April 2020 and no later floating charge ranks equally with it or ahead of it (SI 2020/211, article 2). No prescribed part applies to a floating charge created before 15 September 2003.
Set by law: The two percentages, the £10,000 band and both caps.
Set by you: The net property figure and the date the floating charge was created.
Leaves out: It takes one charge date. With several floating charges of different dates, check which one ranks first before choosing the cap. It also assumes the figure you enter is already net of insolvency expenses and preferential creditors. The waterfall below works that out for you.

Borrowing base calculator

Works out: A rough borrowing base for an asset-based lending facility.
Method: Each asset class (eligible debtors, stock at net orderly liquidation value, plant and machinery at forced-sale value) multiplied by its own advance rate, then added together.
Set by us: The default advance rates. They're illustrative round figures we chose, not a published statistic and not any lender's criteria, which is why every rate can be changed.
Set by you: All three asset values and, if you want, all three rates.
Leaves out: The lender's own view of what counts as eligible, concentration limits, reserves, and its valuation and audit. Enter eligible figures only, and treat the result as an estimate, not an offer.

Charge priority waterfall

Works out: Who gets paid what in a liquidation, and where the money runs out.
Method: Fixed-charge assets go to the fixed-charge holder first, with any surplus added to the floating-charge pot. The floating-charge pot then pays, in order: insolvency expenses, ordinary preferential creditors, secondary preferential creditors, the prescribed part, the floating-charge holder, and unsecured creditors. The tool page links each step to the legislation behind it.
Set by you: Every amount, whether the fixed-charge lender also holds the floating charge, and the floating charge's creation date.
Leaves out: Several fixed-charge lenders are treated as one block, so the ranking between them (or anything an intercreditor agreement changes) isn't modelled. Challenges to a charge's validity are flagged in the text, not calculated.

Company size checker

Works out: Whether a company is a micro-entity, small, medium-sized or large for a financial year under the Companies Act 2006.
Method: Two or more of three limits (turnover, balance sheet total, average employees) in section 382, 384A and 465, or the group limits in sections 383 and 466 for a parent, with the turnover limit scaled for a year that isn't twelve months. A change only counts once it has happened in two consecutive years. For financial years beginning on or after 6 April 2025 the new limits apply to both years, as SI 2024/1303, regulation 3 requires.
Set by law: Every limit, the two-year rule, and the exclusions in sections 384, 384B and 467.
Set by you: Both years' figures, the size the company qualified as last year, and which exclusions apply.
Leaves out: It doesn't check how the employee average or group aggregates were worked out, and it doesn't test a parent for micro-entity status, which needs the parent's own figures as well as the group's. It covers the Companies Act accounting size only, not other definitions such as the SME test for R&D relief.

Retention release estimator

Works out: How much retention a construction contract holds, when each part falls due for release, and what arrives after a CIS deduction.
Method: The retention percentage applied to the value of the work, split between practical completion and the end of the defects period, with dates counted in calendar months. CIS is taken off each release at 20%, 30% or 0% after materials are excluded, at the status that applies on the day the retention is paid, as HMRC's CIS 340 guide, paragraph 6.13 says.
Set by law: The CIS deduction rates and the rule that a release is taxed at the status on the day it's paid.
Set by you: The value, retention percentage and release split, the completion date, the defects period, the payment period, the materials share, your CIS status and, if you want a cost of waiting, your own borrowing rate.
Leaves out: Set-off for defects, disputes, contra-charges and an insolvent payer, any of which can reduce or stop a release. The optional cost of waiting counts from practical completion only.

Duty deferment guarantee estimator

Works out: The monthly deferral limit to ask for, how much of it a guarantee waiver or reduction covers, and how much would need a guarantee, for a Great Britain or Northern Ireland duty deferment account.
Method: The busiest month's Customs Duty, excise duty and deferred import VAT plus your headroom gives the limit. In Great Britain that is tested against the two waiver types in HMRC's guarantee waiver guidance: up to £10,000 a month on the compliance and positive net assets test, above that only if net assets excluding goodwill exceed the waiver, otherwise a partial waiver of £10,000 with the rest guaranteed. In Northern Ireland a customs comprehensive guarantee covers the whole amount, with Customs Duty at 30% for AEOC holders, as HMRC's CCG guidance says.
Set by HMRC: The £10,000 waiver tier, the waiver conditions, the AEOC waiver and the 30% AEOC rule for Customs Duty under a CCG.
Set by you: The busiest month's amounts, your headroom, your net assets figure, your answers on the waiver test and, if you want a yearly cost, your guarantor's quoted fee.
Leaves out: HMRC's own decision on the application, reduced-security schemes for excise duty and import VAT, and it only notes, rather than works into the main answer, a specified waiver between £10,000 and your net assets.

Facility switch cost estimator

Works out: The one-off cost of moving or adding a secured facility, split between leaving the old facility, consent and intercreditor costs for lenders staying in place, setting up the new one and Companies House, and the months the yearly saving takes to pay it back.
Method: Percentage fees applied to the limit or balance you enter, notice not given multiplied by the monthly charge you enter, per-lender consent and legal costs multiplied by the number of lenders staying in place, and each new charge at the registration fee in Companies House's fees list. Payback is the total divided by the monthly saving.
Set by Companies House: The charge registration fee, online and on paper.
Set by you: Every other figure: exit, early repayment and break costs, notice terms, release, consent and legal fees, the arrangement fee, due diligence costs and both facilities' yearly running costs.
Leaves out: Any estimate of what a lender would charge, whether a staying lender will consent at all, the funding cost of any gap between facilities, interest on the money spent and the new facility's own exit costs later.

Facility eligibility checker

Works out: Which type of facility fits the shape of your funding gap.
Method: One to three questions, depending on your first answer, routed the same way as the six situations on the homepage. There are no scores or weightings.
Leaves out: Whether any lender would approve you. It points to a category of facility, not a decision.

R&D notification deadline checker

Works out: The last day to notify HMRC of an R&D claim for an accounting period, and whether the three-year exemption is likely to apply.
Method: The notification window ends six months after the end of the period of account (HMRC manual CIRD183000). The exemption test is applied to your answers about earlier claims.
Leaves out: Whether the work qualifies as R&D, and the Additional Information Form every claim needs whether or not it had to be notified. An accounting period that doesn't match the period of account needs checking directly.

R&D scheme checker

Works out: Whether an accounting period falls under the old SME and RDEC schemes, the 2023-24 transition window, or the merged scheme, and whether ERIS is worth checking.
Method: The period start date against HMRC's scheme dates, then loss-making status, then R&D spend divided by total spend against the 30% intensity threshold for periods beginning on or after 1 April 2024 (HMRC manual CIRD123000).
Leaves out: Connected companies. HMRC's intensity test adds their figures together, and the checker only uses the ones you enter, so treat the percentage as an indication.

R&D claim value estimator

Works out: What a claim for an accounting period beginning on or after 1 April 2024 is worth in the period: Corporation Tax saved, cash paid, and what is held back or carried forward, under the merged scheme and, where a loss-making SME may qualify, under ERIS.
Method: Qualifying spend, with unconnected subcontractor and worker payments at 65%, times the 20% merged scheme credit, run through HMRC's payment steps: Corporation Tax for the period first, then the notional tax deduction at 25% or 19%, then the PAYE cap (HMRC manual CIRD112100). For ERIS, the 86% extra deduction and a 14.5% credit on the lower of 186% of qualifying spend and the unrelieved loss (CIRD122000). Every build checks the module still reproduces HMRC's two worked examples there.
Set by HMRC: The 20%, 86%, 186% and 14.5% rates, the 30% intensity threshold, the £20,000 plus 300% PAYE cap, the 65% restriction, and the 19% and 25% Corporation Tax rates with Marginal Relief.
Set by you: The costs, the trading result and other profits, associated companies, PAYE and NIC, and your answers on the cap exemption, SME status and intensity.
Leaves out: Whether the work qualifies, amounts brought forward, group surrender, other HMRC debts, periods shorter than 12 months, ring-fence trades and Northern Ireland ERIS rules. Its intensity figure uses only the company's own costs.

R&D enquiry risk score

Works out: How many of the features HMRC's own reporting and guidance link to wrong R&D claims are present in one claim, split into validity problems, serious markers, evidence weaknesses and profile features, and a level from those counts.
Method: Claim size and sector count as profile features when HMRC's random enquiry sample found more than the 25% all-claims figure of their value non-compliant; a first claim counts on the same evidence (HMRC's approach to R&D tax reliefs 2023 to 2024, annex B). Evidence weaknesses follow HMRC's Guidelines for Compliance GfC3. The level is our own rule, printed on the page.
Set by HMRC: The non-compliance figures by size, sector and first claim, the sectors it targeted with education letters, the nominee account finding and the GfC3 expectations.
Set by us: Which features count, the groups, and how counts become a level. HMRC doesn't publish its risk rules.
Leaves out: Whether the work qualifies, and HMRC's random selection. The sample is of SME claims received in 2021 to 2022, before claim notification and the Additional Information Form.

Facility guidance

How often the rest of the site is due a check

The facility, sector and R&D guidance pages don't run on a dataset. They're written to the editorial standards, which require every specific figure to link to its source. Every page sits in a freshness class that sets how often it's due a check against its sources:

Class	Meaning	Check due every	Pages
F1	High volatility	31 days	5
F2	Regularly changing	92 days	10
F3	Annual	365 days	10
F4	Evergreen	365 days	97
F5	Static/historical	No fixed cycle	1

A page only shows "Last reviewed" once someone has checked it against its sources and logged that check. Pages without a logged review show "Last updated" instead, which only means the content changed.

Dates

Where every date on this site comes from

Dates come from a logged record of publications, updates and reviews, not from when the site was last rebuilt. Rebuilding or redeploying the site never changes a page's date. When data a page shows changes, that page's "Last updated" date moves, but it doesn't count as a review. Changing a data file isn't the same as checking the page it appears on.

The record started on 17 September 2026. For changes made before then, dates were taken from the site's version history, and each one is labelled that way in the record.

Corrections

What happens when something is wrong

The fix goes on the page it affects. The rule timeline also adds a dated correction note to the entry itself, as on the advance assurance entry corrected on 15 September 2026, because the timeline's job is to show what was known when.
Unsupported claims don't stay as fact. If we can't source something, it's rewritten to say only what the source supports, or removed.
Material changes are logged below. That means anything that changes a figure, a date, a source or a tool's verdict. Wording and layout changes aren't listed.

Changelog

Every material change to the datasets and tools

Date	Asset	Change	What changed
24 September 2026	Facility switch cost estimator	Published	First published on this site.
23 September 2026	R&D claim value estimator	Published	First published on this site.
23 September 2026	R&D enquiry risk score	Published	First published on this site.
23 September 2026	Charge priority waterfall	Published	First published on this site.
23 September 2026	Company size checker	Published	First published on this site.
23 September 2026	Duty deferment guarantee estimator	Published	First published on this site.
23 September 2026	Retention release estimator	Published	First published on this site.
22 September 2026	Borrowing base calculator	Published	First published on this site.
22 September 2026	Prescribed part calculator	Published	First published on this site.
15 September 2026	Facility eligibility checker	Fixed	Every question used to have an answer ticked in advance, so the checker showed a result before you'd answered anything. Nothing is pre-selected now, and no result appears until the questions that apply have been answered.
15 September 2026	R&D adviser register	Revised	Firm profiles rewritten as neutral summaries of what each firm publishes. Internal research notes and panel-style judgements came out of the register and its schema. The 9 August check dates were kept, because no firm was re-checked in this pass.
15 September 2026	R&D tribunal case tracker	Revised	Source labels now say plainly where we couldn't find a full decision on a free public site. Notes about how the tracker itself was built came out of the visible copy.
15 September 2026	R&D notification deadline checker	Corrected	Where the notification deadline had passed, the checker told every company that a claim couldn't be made, including companies that had answered as likely exempt under the three-year rule. It now checks the exemption first, so an exempt company is told the passed deadline only matters if the exemption doesn't apply. It also waits for every question that applies before giving a verdict.
15 September 2026	R&D rule timeline	Corrected	Targeted advance assurance pilot entry: it had carried dates from earlier research, including a 31 May 2027 end date, with no primary source. It was re-checked against gov.uk, now uses HMRC's own wording (the pilot runs "until May 2027"), and carries a visible correction note on the entry itself.
15 September 2026	R&D scheme checker	Fixed	The checker had "not loss-making" ticked in advance, so it gave a verdict nobody had asked for. It now waits for that answer. It also rejects intensity figures that can't be right (a negative value, or R&D spend above total spend) instead of working out a percentage from them.
14 September 2026	R&D scheme checker	Fixed	A script fault meant the checker returned no result for any input. It was reproduced in a real browser, fixed, and re-tested across four scenarios: pre-reform, the 2023-24 transition window, merged scheme with ERIS possible, and merged scheme for a profitable company.
13 September 2026	Facility eligibility checker	Corrected	The page said the checker took three questions. Depending on your first answer it asks one, two or three, so the wording now says "a few quick questions". The routing itself didn't change.
7 September 2026	Facility eligibility checker	Published	First published on this site.
11 August 2026	R&D adviser register	Corrected	Registration finding: removed a statement that HMRC had confirmed it would not publish a register of registered tax advisers, because we couldn't source it.
11 August 2026	R&D tribunal case tracker	Corrected	Stage One Creative Services Ltd v HMRC ([2024] UKFTT 1059 (TC)): removed a decision date of 25 November 2024. BAILII's page title shows 25 November 2023 against a 2024 citation, and we couldn't resolve the mismatch, so the tracker now gives no single date and says why.
11 August 2026	R&D rule timeline	Corrected	Adviser registration entry: removed a statement that HMRC had confirmed it would not publish a register of registered tax advisers, because we couldn't source it. The entry now says only what HMRC's registration guidance shows: no way for a client to check whether a firm is registered.
9 August 2026	R&D adviser register	Published	First published on this site.
9 August 2026	R&D tribunal case tracker	Published	First published on this site.
9 August 2026	R&D notification deadline checker	Published	First published on this site.
9 August 2026	R&D rule timeline	Published	First published on this site.
9 August 2026	R&D scheme checker	Published	First published on this site.

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Adam Parker

Founder of Muswell Rose Consulting Ltd, which trades as Established Finance · former Managing Director of Penny, an invoice finance business, working in mortgages, commercial finance and fintech lending since 2010 (career history).

Last reviewed: 24 September 2026