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A company’s books as its adviser reads them. journal: the libro diario in date order; account lists an account’s ledger (libro mayor), each entry with only that account’s lines. trial_balance: the year’s sumas y saldos from 1 January to to, by account the opening balance, debit, credit and closing balance (debit positive); groups 6 and 7 start the year at zero and earlier results not yet applied show where the books reopened them (129 or 120); without prefix it groups by 4 digits, and at most 400 accounts are listed (accounts_omitted counts the rest: narrow with prefix). statements: the annual accounts in the PGC’s normal model (pérdidas y ganancias, balance) beside the year before; detail adds each line’s accounts. corporate_tax: the year’s Impuesto sobre Sociedades (modelo 200) from the books and the saved inputs, the 202 instalments it sets with their deadlines, and review codes to check; its rate’s kind is general (25 %), small_company (empresa de reducida dimensión: the year before’s turnover under 10 M€, art. 101 LIS: 24 % in 2025, 23 % in 2026), micro_company (under 1 M€) or new_entity (15 %). Each 202 instalment’s amount is what the company pays, by its method: 40.2 is 18 % of the last return’s cuota (on_last_return); 40.3 is the year’s base so far at period_rate, 5/7 of the year’s rate rounded down: 16 % for 23 %, 17 % for 24 % or 25 % (on_period_base), and is compulsory above 6 M€ of turnover (compulsory_period_base). Its version is the expected_version of corporate_tax_update and corporate_tax_filed. corporate_tax_update saves only the fields supplied and answers the recalculated tax; a year whose 200 was filed (filed) changes only with rectification, when the person asks to rectify that return. corporate_tax_filed records a 200 filed outside Melso (the day and the result filed, which must equal Melso’s calculation): the 202 instalments then build on the return filed (art. 40.2), whatever the year’s books or inputs say later. Amounts are EUR decimal strings. No action approves, files or pays a return. Each action accepts only its own fields (* required): journal(account, cursor, from, limit, to); trial_balance(year*, digits, prefix, to); statements(year*, detail); corporate_tax(year*); corporate_tax_update(year*, expected_version*, adjustments, capitalization_reserve, deductions, instalments, losses_offset, new_entity, period_base, prior_turnover, rectification, withholdings, workforce_growth); corporate_tax_filed(year*, expected_version*, filed_on*, payable*). Availability: Empresa. The live tool list is authoritative: the company’s plan and your role can narrow this contract. Understand access.

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When to use

Use it to read an empresa’s books the way its adviser does: the journal and an account’s ledger (journal), the trial balance (trial_balance), the annual accounts (statements) and the year’s corporate tax with its 202 instalments (corporate_tax). It is listed only for an empresa with accounting; corporate_tax_update, which saves what the books cannot say (adjustments, the capitalization reserve, deductions), also needs a plan with the tools. The owner still approves the 200 in the app.

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Input

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Actions

The tool’s schema combines the fields of every action. Each action accepts only its own fields below; send action with them.

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Read actions

These actions only read. They change nothing.
The year’s corporate tax (Impuesto sobre Sociedades, modelo 200) as Melso calculates it from the books and the saved inputs: result before tax, adjustments, capitalization reserve available and applied, negative bases, taxable base, rate, cuota íntegra and líquida, withholdings, instalments paid and what is left to pay, deferred tax and the books’ charge; plus the 202 instalments that build on it, with deadlines. filed is the 200 filed for the year (null until it is recorded or Melso files it; differs when Melso’s calculation no longer gives it), and once it is there the instalments build on it (last_return_filed). deadline_passed: the 200’s deadline is over, so the year was most likely filed. review lists what to check. version is the expected_version for corporate_tax_update and corporate_tax_filed.
The company’s libro diario in date order: each entry’s number, kind (opening, normal, regularization, closing), source and lines with account, name, concept, debit and credit. account lists an account’s ledger (libro mayor): only the entries that move an account starting with those digits, each with only that account’s lines (other_lines counts the rest). A full page carries next_cursor.
The year’s annual accounts in the PGC’s normal model: the profit and loss account (cuenta de pérdidas y ganancias) and the balance sheet at the year’s end, each line keyed as the modelo 200 files it, beside the year before. detail adds the accounts behind each line.
The year’s trial balance (balance de sumas y saldos) from 1 January to to: by account, the balance carried into the year, the year’s debit and credit and the balance at the end (debit positive, credit negative). Groups 6 and 7 start the year at zero; earlier results not yet applied show where the books reopened them (129 or 120). Without prefix it groups by 4 digits; with prefix it shows the full subaccounts that start with it. At most 400 accounts are listed; accounts_omitted counts the rest.

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Write action

It saves the corporate tax’s inputs and needs a plan with the tools. It does not approve or file the 200.
Record that the year’s 200 was filed outside Melso, as by the company’s previous adviser: the day and the result filed (casilla 01586 of the return, negative for a refund), which must equal what Melso calculates for the year (corporate_tax_get); when it does not, the answer refuses with Melso’s figure, and the adjustments or inputs need correcting first. The 202 instalments then build on the return filed and a later change to the year is a rectification. Record a rectification filed later the same way. It files and pays nothing.
Save what the year’s corporate tax needs beyond the books, at expected_version from corporate_tax_get: only the fields supplied change. Answers the recalculated tax. It does not approve or file the 200: the owner approves the return in the app and Melso’s professionals file it.

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Output

journal returns the entries in date order, each with its lines; a full page carries next_cursor, and with account each entry keeps only that account’s lines (other_lines counts the rest). trial_balance returns each account’s opening balance, debit, credit and closing balance, and accounts_omitted when it lists only the first 400. statements returns the profit and loss account and the balance sheet beside the year before. corporate_tax returns the modelo 200 calculation, the 202 instalments it sets, review codes and its version. corporate_tax_update returns the recalculated tax. None of these approves, files or pays a return. The result uses MCP content blocks; JSON payloads are encoded in text and may also appear in structuredContent. Check isError before reading a success payload. The server does not declare an outputSchema, so rely on the fields named here and in the live result.

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Example

Explain an empresa’s corporate tax for 2025 and save an adjustment the person gives you. These are the arguments of each call, in order.
1

Check the tax accounts in the trial balance

2

Read the corporate tax and note its version

3

Save a non-deductible fine at that version

The first call as a request. Use an OAuth access token issued for this MCP resource and replace the example identifiers with values from your own company. Write actions change data.