How Collider works.

What comes back

The tax

One amount, computed by the rules. When a payment is taxed on both sides there are two lines: what the payer withholds, and the recipient’s own tax.

“based on 4 assumptions”

How many unstated facts the figure rests on. Open it for the list; to change one, tell the agent.

Stated by you

What you stated, said back as you gave it.

A few questions

Only when a fact nobody stated would change the figure.

Needs legal review

The one warning, described below.

The law used

Every rule the figure rests on, with its paragraph. Each opens on the law’s own sentence.

Save

Keeps the result as it is.

Amounts are rounded the way the act itself says (§ 47): every computation to two decimal places: the second digit stays when the next is below five, and rises by one when it is five or more.

One situation, followed

A case from the set Collider is tested on, with its real figures. Very little was said; the rest was assumed and listed.

What was said

“He lives in Slovakia. He founded a Slovak s.r.o. and on 1 June 2026 sold 40 % of it for 300 000,00 €. Of what he had paid in, 2 000,00 € belongs to the part he sold.”

The tax

94 718,02 € under § 15 písm. a) bod 1

Assumed

Based on 4 assumptions

• Partial base from employment: 0
• Special base under § 7: 0
• First day of the tax period: 1 January 2026
• Last day of the tax period: 31 December 2026

From an official source

• Subsistence minimum at 1 January: 284,13 €opatrenie MPSVR SR č. 168/2025 Z. z., § 1 ods. 1 písm. a)

How it came about

1. The expense: the contribution paid in for the part sold§ 8 ods. 72 000,00 €
2. What stays taxed after the exemption§ 9 ods. 1 písm. i)297 500,00 €
3. The tax base§ 4 ods. 1 písm. a)297 500,00 €
4. The tax on each band of the scale8 356,83 €4 091,47 €4 398,33 €77 871,39 €
5. The tax§ 15 písm. a) bod 194 718,02 €

Asked

Nothing: no rule was left waiting on a fact.

Legal review

Not needed.

A fact nobody stated is taken as:

A yes or no

no

A choice between several, a date or a text

none

An amount or a number

0

A set of several values

empty

When things happen is taken from the day you ask about:

First day of the tax period

the first day of that year

Last day of the tax period

the last day of that year

Calendar month assessed

the first day of that month

Date the income is paid

that day

Day the income was received

that day

Assumptions that carry the figure are listed by name. The rest change no figure and are only counted. The agent may also assume something itself, with a one-line reason, so that you can correct it.

To change an assumption, say so: “He also draws a salary from his company.” The situation computes again with that fact.

Never assumed: an amount another law sets

An amount another law sets for a period is never taken as 0. It comes from its official source, named beside it. For a period with no amount held, Collider asks.

Subsistence minimum at 1 January

• 284,13 € for 2026opatrenie MPSVR SR č. 168/2025 Z. z., § 1 ods. 1 písm. a)
• 295,22 € for 2027opatrenie MPSVR SR č. 155/2026 Z. z., § 1 písm. a)

Set by Zákon o životnom minime (601/2003 Z. z.); the Slovak Income Tax Act reads it at § 11 ods. 2 písm. a).

Never assumed: a state’s place on an official list

What you state stands

You may state anything, a legal classification included (“this income is exempt”). It is used as you stated it, listed as stated by you, and no rule overrides it.

You can also state what a law Collider does not hold says, for this situation alone:

• a rate, as a per cent of an amount you name
• an amount of tax
• that the income is exempt there
• a fact that law decides, which the Slovak rules then read

It gets a line of its own and is never added to the Slovak figure.

Questions

Collider can name the unstated facts most likely to change the figure, never more than 5. The agent passes on only the one that matters; most results come with none.

1. The result rests on two rules that are known to conflict: both apply and the law does not say which gives way. Only a conflict we have examined and confirmed is flagged.

   Needs legal review. One rule and another both apply here and the law does not say which gives way.

2. A rule that produced the figure has an exception (“unless”, “except”) that could not be checked from the facts given.

   Needs legal review. An exception to a rule that produced the figure could not be checked.

The figure still stands as computed. The line says that at this point the law does not settle the matter by itself, or that an exception stayed open. Have that result reviewed by a tax advisor or a lawyer before you rely on it.

A result without the line was not flagged. That is not a legal opinion either.

Entities

A map holds 7 kinds of entity: company, person, trust, fund, foundation, partnership and branch. Each has a country and a legal form, and can hold further details: the country where it is tax resident, its registered seat, its register number, its share capital, the day it was incorporated, a stake, the class of shares, the price paid for a stake, a voting share, a profit share, a role someone holds at it, the principal of a loan it gave and a clause of an agreement with another entity.

An entity is pending, active, in liquidation or dissolved. One that is in liquidation or dissolved can no longer be changed.

Who owns what

What ties two entities is one of 13 kinds of relation.

In per cent

A stake, votes, a profit share, an option and a convertible.

Without a number

A trust’s settlor, its trustee, its protector, its beneficiary, a general partner, a limited partner, a nominee and a registered role.

A change that cannot be true is refused, changes nothing and says why:

• “A stake cannot be above 100 %.”
• “Together its owners would hold more than 100 % of it. Lower another stake first, or say it as a transfer.”
• “The holder does not own that much to transfer.”

Dates

Everything on a map holds from a date and, where it ends, until one. So a map is not one picture: ask for it as it stood on any day, and that is what is drawn and what is computed on. Save keeps the map as on its date.

History and Undo

Every change is dated and named in the history in one sentence, newest first. Undo takes the newest change back by making the changes that put the map back. Nothing is erased, so the history shows both.

What can change:

Entities

Add one; rename it; change its country, legal form or status; change its tax residency; close it by liquidation; merge two; split one off.

Ownership

Add a stake or another relation; transfer shares; issue new shares, which dilutes the others in proportion; end a stake or a relation; add a trust relation; appoint someone to a role.

Payments

Add a payment, once or repeating; correct one; remove one entered in error; contribute capital; grant a loan.

Details and duties

Set a detail; add a duty; mark a duty met; remove a duty entered in error.

A duty is something an entity owes by a date, or every year, quarter or month: a filing, a register update, a licence condition, a substance requirement, a report, a covenant and anything else, in your words. Duties are kept as you state them.

Questions a map answers

Asked on any date, each answer comes with the steps it took, and the agent lights the entities up on the map.

What does someone really own?

Everything a holder owns, directly and through every chain of companies. Circular holdings are solved exactly.

What does someone control?

Every entity where the holder’s votes are above a threshold.Above 50 % unless you say otherwise.

What belongs to a group?

The entity at the top and everything it controls, layer by layer.Above 50 % unless you say otherwise.

Since when has a stake been held?

Since when a holder has held at least a given share of an entity.

Who stands behind an entity?

The chains of ownership from an entity up to the people at their ends.

Which borders does a holding cross?

The paths of ownership between two entities and the borders each crosses.

Collider’s own example maps can be opened, read and computed on. They cannot be changed or saved on a date.

Computed: 9 kinds of payment

Dividend

A share of profit paid to an owner.

Interest

Interest on a loan or another debt.

Royalty

A payment for the use of a right: software, a patent, know-how, a copyright, equipment.

Fee

A payment for a service: advice, management, data processing, marketing, construction and others.

Wage

Pay for work, under an employment contract or a similar relation.

Sale of a stake

The sale of a stake in an s.r.o., a k.s. or a cooperative.

Sale of shares

The sale of shares of an a.s. or of other securities: bonds, fund units.

Sale of real estate

The sale of a flat, a house, land or another building.

Sale of an enterprise

The sale of a business, or a part of it, as a whole.

Shown on the map, not computed: 4 kinds of payment

Loan paid out

A loan paid out to the borrower.A loan paid out moves principal, not income. There is nothing in it for the rules to tax.

Loan repaid

A loan paid back.A repayment returns principal, not income.

Capital contribution

Capital paid into an entity.The rules on contributions need accounting figures that a map does not hold.

Distribution

A payout that is not a dividend.The map does not say which kind of payout it is (a liquidation share, a payout from a capital fund, a settlement share), and the law treats each differently.

A payment of any kind with neither side in Slovakia is shown and not computed: Slovak law does not reach it.

A payment is computed for the recipient. Ask, and it is computed for the payer’s own tax instead: whether the payer may deduct it, for example.

Beyond who pays whom, how much and when, a payment carries what the law needs to know of its kind. A dividend: the year whose profit is paid and the day the payout was decided. A sale: when and how the seller acquired the thing, and what it cost. A fee, a royalty or a wage: the kind of service, right or work relation.

Real cases

5 payments from Collider’s example maps, with the tax the rules compute for each.

The figure follows the facts. The same kind of dividend is taxed at a different rate when its recipient lives in a state that is not on the list of cooperating states.

What it decides by itself

• Which areas of law and which rules fit. A rule it judges not to belong to the situation it sets aside, with a reason you see.
• Which facts your words state. Where it must assume something itself, it says so, with a reason.
• Which of the possible questions matter. Most do not; it asks only the one whose answer would change the figure.
• What to show first, and how to say the result plainly.

What it does when you ask

• Computes a situation, from your words or from a payment on a map.
• Builds a map from a description, and changes one a dated change at a time.
• Answers who owns what and lights it up on the map.
• Takes the last change back, saves a result or a map, and explains a rule a result used.

What it never does is arithmetic. Every number it mentions comes from the rules or from you.

A follow-up changes one thing. “And if he had sold the whole company?” computes the same situation again with that one fact changed.

If the agent cannot be reached, it says so in one sentence. There is no form to fall back on.

1. In your chat’s settings, add a custom connector and paste the address below.
2. A window opens on Collider’s own sign-in: your e-mail and the six-digit code. It is the same account as on the website.
3. Allow the connection. Deny returns you to the chat with nothing connected.

What it can do there

• Compute a situation, and explain a rule a result used.
• Say which areas of law compute and which facts their rules read.
• Read, build and change your maps, read their history and take the last change back.
• Answer the questions a map answers.
• Save a result or a map, list what you saved and check it.
• Hand the whole job to Collider’s agent and bring its answer back.

Computation only. In your chat, as on the website, Collider does not read out or search the text of the law; that is the work of Legible.

The example maps stay read-only there. Each thing your chat does is recorded as on the website: what was done, never the words or values you gave.

To disconnect, remove the connector in your chat. A connection left unused for thirty days asks you to sign in again, and deleting your account ends every connection at once.

Collider computes from one act today: the Slovak Income Tax Act (Zákon o dani z príjmov, 595/2003 Z. z.), with 1,225 rules in 124 of its 181 sections. Each rule is written from one sentence of the act and shows that sentence.

The areas the agent chooses from

A rule can belong to more than one area, so the areas add up to more than the act holds.

The act, part by part

A section with a rule is not a section computed whole. The Law pages list every rule in plain words, with the paragraph it rests on.

When the act changes

Collider already holds the wordings of the act that come into force later. A rule whose sentence reads the same carries over. A rule whose sentence changed does not compute for days under the new wording.

From 31 December 2026: 1,213 rules.

Fewer than today in § 8 (48 of 51), § 9 (56 of 57), § 11 (12 of 20).

From 1 January 2027: 1,209 rules.

Fewer than today in § 8 (48 of 51), § 9 (56 of 57), § 11 (12 of 20), § 25 (5 of 6), § 29 (2 of 5).

Held beside it

EU Parent-Subsidiary DirectiveEU directive

Council Directive 2011/96/EU of 30 November 2011 on the common system of taxation applicable in the case of parent companies and subsidiaries of different Member States (recast)3 rules

Slovakia–Czechia tax treatyTreaty

Oznámenie Ministerstva zahraničných vecí Slovenskej republiky o uzavretí Zmluvy medzi Slovenskou republikou a Českou republikou o zamedzení dvojitého zdanenia a zabránení daňovému úniku v odbore daní z príjmov a z majetkuNo rule computes yet.

The rules read 681 different things about a situation. 574 are facts that you or your map state: who the taxpayer is, what was paid, how an asset was acquired. 107 are classifications the law itself decides from the facts, such as whether an income is exempt; you may state one yourself, and then it stands as you stated it. 79 of the facts are defined by another law, such as the Accounting Act.

You say what happened, the agent states the facts your words contain, and everything else is an assumption until you say otherwise. The groups below show what the rules can take into account.

And smaller groups: The payer 17 · Benefits and gifts 16 · The employer 14 · Activities 13 · Reserves 12 · Contributions 11 · The company itself 10 · The tax period 10 · Children 6 · A predecessor 4 · A debtor 3 · The spouse 3 · Others caring for the child 2 · A successor 2 · The recipient 1.

Not yet

• Only the Slovak Income Tax Act computes. No VAT, no social or health insurance, no other tax and no other country’s law. An amount those set, such as the insurance withheld from a wage, is a fact you state.
• Tax treaties. The Slovakia–Czechia tax treaty is held and computes nothing; no other treaty is held. The figure for a cross-border payment is the act’s own, before any treaty. You can state what a treaty says, and it is shown on a line of its own.
• The EU Parent-Subsidiary Directive is held, but its rules do not reach a result yet. A dividend to a parent company in the EU is computed from the Slovak act alone.
• Some sections compute less under the wordings of the act that come into force later, as listed above.
• 4 kinds of payment are shown on a map and not computed: loan paid out, loan repaid, capital contribution and distribution.
• Duties are kept as you state them. Collider does not derive them from the law.
• Collider knows only what you put on a map or say. It looks nothing up in a company register or any other outside source.

Not at all

• No advice. See the next section.
• No reading or searching the text of the law. The Law pages show only the rules Collider computes with, each with the paragraph it rests on.
• No API and no keys. You compute on the website or in your own chat, signed in.
• No forms to fill in, and no picking areas of law by hand.
• No refusing to compute for a missing fact, and no hidden assumption.
• No arithmetic by the agent.
• No filing. Collider prepares no return and sends nothing to any authority.

The facts are yours.

Collider does not verify what you state or what is on your map. Read the assumptions: each is a fact taken as not the case because nobody said otherwise. If one is wrong, the figure is wrong until you correct it.

The law is the official text.

Every rule is written from one sentence of the act as officially published, and shows that sentence. Where a rule and its sentence seem to differ, the sentence is the law.

The rules are tested, not guaranteed.

They are checked against the tax office’s own published examples and against cases worked out by hand. This is a beta, and a rule can still be wrong.

The decision is yours.

Before you file, pay or sign on the strength of a figure, have it reviewed by a tax advisor, and always when the result says it needs a legal review.

Getting in

Open to anyone. You sign in with your e-mail and a six-digit code, and your first sign-in makes your account; there are no passwords. The mail that carries the code does not mention Collider by name.

Yours alone

Your maps and saved results are open to your account only. Every read and every change is checked against who holds them.

Where it is kept

Your account, your maps and your saved results are stored in the European Union.

The agent

The agent is a language model run by an outside provider. What you type, and what it reads from your maps to answer you, passes through that model.

What is recorded

That you signed in and, for each thing the agent or your chat did, what was done, when, how long it took and whether it worked. Never the words you typed or the values you gave.

Settings

Change your name or your e-mail address, write to support, or delete your account. Deleting is immediate and cannot be undone: your account, every map of yours, what you saved, what you wrote to us and your chat connections are deleted.

Your choices

English or Slovak, light or dark, sounds on or off. Each is kept in your browser.

A beta

Things change, and Collider may at times be unavailable. What it covers on a given day is on this page, read from Collider itself.