Your judgement is the scarce part. Learn to make it run.

Writing the rules of a law as a program that computes an outcome from facts, so the rule can be tested, versioned and diffed like any other code.

In tax terms · Instead of a spreadsheet that applies the small-companies rate, a function that reads "turnover" and "year" and returns the rate, with a test for every threshold in the statute.

A program that takes a taxpayer’s facts and returns a computed liability, return or forecast, deterministically: the same input always gives the same answer.

In tax terms · The thing a compliance suite sells per entity. Open tax-benefit engines model whole tax systems for more than fifteen countries; none yet does corporate provision or Pillar Two.

A language model given tools and a goal, that decides which tool to call next, reads the result, and continues until the goal is met or it stops to ask.

In tax terms · An agent can validate 50 VAT numbers, read the results, flag the three that failed and draft the email. It should not decide whether the reverse charge applies without a person reading the memo.

A short document (usually a SKILL.md file) that tells an agent how to do one job: the steps, the sources to use, the checks to run, when to stop.

In tax terms · Packaged expertise. "Check EU reverse charge: confirm both parties are taxable persons, validate the VAT number via VIES, apply Art. 44, cite Art. 196, flag exceptions." A fiscalist can write one without code.

A small program that exposes tools to an agent through the Model Context Protocol, an open standard: each tool has a name, inputs, and a description the agent can read.

In tax terms · The adapter between an agent and a tax source. One MCP server offers "validate_vat_number"; another offers Brazilian NF-e lookups; another exposes a whole tax-benefit model.

A bundle of skills, MCP servers and settings that installs into an agent product in one step.

In tax terms · The way a firm would hand every adviser the same reverse-charge skill, the same VIES tool and the same citation rules at once.

An address a program can call to get data or an action back, with a defined format for the request and the reply.

In tax terms · VIES has one: send a VAT number, get back valid or not. Every e-invoicing regime has one. Most tax authorities are building more.

Facts in a machine-readable, versioned form: a table or a corpus with a licence and a change history.

In tax terms · VAT rates by country and date. Every ATO ruling as text an agent can search. The difference from a PDF is that a program can read it and you can see what changed.

A fixed set of test cases with known correct answers, used to measure how often a model or engine gets them right.

In tax terms · TaxCalcBench scores engines on real US returns. SARA tests statutory reasoning on the tax code. Ask a vendor for its benchmark score before its demo.

Filing and payment deadlines as structured data (jurisdiction, obligation, due date, rule), not as a PDF or a wall chart.

In tax terms · The input an automation needs to chase the right person three weeks before a deadline. One open project exists, for retail fiscal calendars. None covers a multinational's filing deadlines.