Built by paraplanners, for paraplanners.

Two load-bearing calculations, and the suite around them.

Pension annual allowance — including taper, carry-forward, and MPAA — plus investment-bond chargeable-event gain with top-slicing relief. Those two are the load-bearing calculations. The rest of the suite is built around them and runs on the same engine: the lump-sum allowances, the income-tax and contribution work the pension side leans on, long-term care funding, and pension death-benefit IHT for the April 2027 regime. Most of it is published as a free calculator you can use without an account.

The boundaries are just as deliberate. No lifetime cashflow modelling — cashflow tools produce projections, we produce the figure you sign off, and the two answer different questions. No stand-alone CGT calculator (the wrapper comparison models CGT on a GIA), no SDLT. No general estate or trusts IHT: the inheritance-tax work stops at the pension death-benefit perimeter. No end-client portal. Narrow on purpose.

For a Scottish taxpayer the free bond calculators give the gain and top-slicing relief but do not show tax totals; the bond workbench and its annex do not yet cover Scottish taxpayers. Some onshore cases are refused rather than estimated: in 2026/27, cases with dividends, relief-at-source pension contributions, Gift Aid, more than one gain, deficiency relief or a settlor-charged trust, or above set income, gain or holding-period limits; in 2022/23, cases with dividends, relief-at-source contributions or Gift Aid; and in 2020/21 and 2021/22, some cases with dividends, relief-at-source contributions or Gift Aid. See the limits on the top-slicing relief calculator.

The calc engine is pure deterministic TypeScript. Every rate, threshold, and allowance lives in a versioned tax-year config; every output stamps the config version, so a filed calculation keeps the inputs and rule versions needed to check it years later. Code calculates; AI never does. AI is used in two bounded places: the extraction layer, which pulls figures from uploaded PDFs (P60s, pension annual statements, chargeable-event certificates) — every extracted field passes a user-review gate before any maths runs — and Pan, a read-only, single-client query assistant that narrates the facts already stored on a client record and cites the HMRC rule behind them. It computes nothing.

The output is an A4 compliance annex: the key figures first, any material warnings beside them, the step-by-step working (with the HMRC manual references it follows on the pension and bond annexes), and the complete planning disclosure once after the workings. Every page carries your firm’s name and FCA attribution (where an FCA firm reference number is set), the page number and the preparation date. On Pro and Firm the annex also carries your logo and brand colour where set, and, if your firm owner turns it on, the preparer’s name. The annex does not print the tool version or the config version. Those, the full inputs and the intermediate steps stay on the saved calculation’s audit record and in your firm’s audit export. How we verify the engine covers the regression case table and the additional tests of statutory boundaries, rounding and allowance interactions.

One top-slicing rule is easy to miss.

For gains arising on or after 6 April 2021, HMRC's manual (IPTM3820) says the personal savings allowance and the starting rate for savings must be recalculated at the notional-income level at Step 4 of the top-slicing calculation, rather than carried through from the main calculation.

On the worked £90,000 offshore gain before any TAR our engine pins in CI, carrying the full-gain PSA into Step 4 gives £600 less relief than the recalculation IPTM3820 requires for a 2021/22-onwards gain; the gap depends on the bands the gain and the slice fall in and on the number of complete years. ParaplanAI applies the rule variant matching the gain's tax year — the Step-4 recalculation for gains from 6 April 2021, the carried-forward PSA/SRB method for earlier gains — and the annex states which variant was applied.

Worked-example basis: No time-apportioned reduction is due for any gain or policy shown. TAR is not calculated or applied. Raw gains are shown before any TAR.

The same engine handles tapered annual allowance, carry forward and MPAA, each shown step by step with the HMRC references its working follows.

UK/EU-hosted, you control retention, no surprises.

Client documents, client records and calculations are held in encrypted UK databases and storage, and processed in the UK and EU (document extraction and Pan run on AWS Bedrock within the UK and EU). Some services work outside the UK and EU: payments, the sign-in bot check, and the edge network that carries a request made from outside the UK and EU; our privacy notice, section 5, explains each. Client records are encrypted at the application layer before storage, and the calc engine never sees them; identity details read from documents are encrypted at rest and follow the extraction windows. Uploaded source documents are scheduled for deletion after 24 hours; filed output PDFs stay with their calculation under your firm's retention policy.

Filed results are immutable and keep their inputs and rule versions for later checks; drafts must pass replay verification before filing. You are the controller and hold your own FCA record. Your firm can delete clients and calculations after confirmation, and archive policies while preserving their history. Finalised calculations are kept for the window your firm sets — six years by default.

Sub-processors are listed in our privacy notice, section 4, and a summary of our data processing agreement is at /legal/dpa; the security posture and the disclosure process are on /security.

The brand is the author. The method is the proof.

ParaplanAI publishes under its own name, not a personal byline — the way an institution does. Its authority does not rest on who built it; it rests on a method anyone can check: every figure is derived by deterministic code from versioned tax-year rules, checked against a public table of regression cases with their sources, and shown with its working. Cases the engine cannot work are refused; where HMRC's guidance is ambiguous, a documented reading is applied and kept on record, available on request. The pension and bond annexes cite the HMRC manual sections the working follows. See how we derive and verify every figure.

The product is built and operated by working UK paraplanners, so the rules are read by people who have carried these calculations across real client files, not just coded them. We keep names out of the headline on purpose: the credibility is in the public table of regression cases and the care taken with updates: published HMRC changes are reviewed, tested and released with a version record. The operator’s identity is withheld here but available to professional bodies and prospective firms on request — including a named contracting party for a sub-processor DPA.

Compliance officers and prospective firms can email info@paraplanai.co.uk for the operator’s CV, references, or a screen-share walkthrough of the calc-engine corpus run.

A calculator, not an adviser.

ParaplanAI is a calculation tool. It produces the figure and the working behind it; it does not make recommendations and it does not assess suitability. The regulated adviser who uses it keeps responsibility for the advice given to the client.

Every output carries the same line: for planning and illustration purposes only; this tool does not constitute financial or tax advice.

Common questions.

More answers are on the FAQ and the help page.

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