Strategy
M&A, capital markets, and strategic advisory for transformative deals.
View all StrategyData rooms and transactions. The analysis and the recommendation are signed by the people on the team.
Discover BMC One Strategy Log in to BMC OneFree first meetingBy video call
Tax
Structuring, planning, and compliance across jurisdictions.
View all TaxForms 720 and 721
Filing period from 1 January to 31 MarchForms 720 and 721
The filing period ends on 31 MarchTax authorities, deadlines and powers of attorney. Our team prepares, files and responds.
Discover BMC One Tax Log in to BMC OneFree first meetingBy video call
Legal
End-to-end legal counsel to protect and advance your business interests.
View all LegalSignatures, case files and deadlines. BMC lawyers handle every matter; in BMC One you see its phases and the status of each one.
Discover BMC One Legal Log in to BMC OneFree first meetingBy video call
Operations
Outsourced finance, people, and governance so you can focus on growth.
View all OperationsAccounting, invoices, bank statements and payroll. Our team books, calculates and submits.
Discover BMC One Business Services Log in to BMC OneFree first meetingBy video call
New guides on the latest Spanish tax and immigration developments.
Practical tools for informed decision-making.
Everything BMC One does
Each capability links to its area. Partial: part of it works; the detail is on the area page.
Try
Business Services
Tax
Legal
Security
Nothing for “”. Try “VAT”, “payroll”, or “signature”.
By area
Business ServicesOperations
Your business, up to date in one place
Our team books, calculates and submits.
Ask your assistantExamples
How many active employees do we have, and under which collective agreement and type of contract?
Add these three employees with their DNI, Social Security number and start dateThey stay in BMC One; nothing is notified to Social Security.
Tax
Every Spanish tax deadline, in plain sight
Our team prepares, files and responds.
Ask your assistantExamples
Which returns do we have this quarter and which have already been filed?
Change the tax address on the record to Calle Muestra 5, MadridIt changes the record in BMC One; nothing changes with the AEAT.
Legal
Every phase, with its status and its date
BMC lawyers handle every matter; in BMC One you see its phases and the status of each one.
Ask your assistantExamples
Which documents are still awaiting signature and who has yet to sign?
Prepare an envelope for Lucía Prueba to sign this contract on the last pageIt stays in draft. Sending it is a critical action: only with the Custom role.
Strategy
The whole transaction in one file
The analysis and the recommendation are signed by the people on the team.
Ask your assistantExamples
Find what BMC has written to us about the capital increase
Where do the tax obligations of every company in the group stand, and which one has gaps?With a group access.
Across all areas
ConnectionsAPI, MCP and webhooks
It works with any assistant that supports remote MCP connectors with OAuth sign-in; for example, Claude, which we have tested it with, or ChatGPT Business, Enterprise and Edu, as documented.
With a token, also Gemini CLI, Cursor, n8n, Make or Zapier; and, by API and signed webhooks, your own systems.
No assistant files with the AEAT, moves money or signs for you.
Only with the Custom role, chosen permission by permission.
API and MCPConnect your AIIntegrationsPublic administrations
Security
Its own scoped access, never your session
BMC One, its database and your documents are on our own dedicated servers in Europe. The database is not exposed to the internet.
No assistant files with the AEAT, moves money or signs for you.
Illustration of what you choose when you authorise an access. Fictitious data.
Returns
ReturnsForms 720, 721 and 210
Returns for investors and non-residents
Assets held abroad, crypto assets and non-resident income, at two levels: Platform and With an adviser.
BMC's client environment, included in your engagement: never sold separately.
Doctrine by topic · DGT Observatory
How the DGT's position on this topic has evolved, and the rulings it rests on.
Current position
Self-assessment must be submitted quarterly via electronic means, even when the result is zero euros due to exempt operations. In the case of plastic packaging, self-assessment requires registration in the territorial registry and compliance with accounting obligations. For IRPF (Personal Income Tax), refunds are governed by the General Regulation of tax management and inspection proceedings.
The DGT's position does not show a doctrinal evolution regarding the concept of self-assessment, as the rulings concern different tax matters (Conventions, IRPF, LIE, IEDMT). Each ruling establishes specific self-assessment requirements for the specific tax being analyzed, without a common thread of changing criteria.
Turning points
Establishes the obligation to submit quarterly self-assessment via electronic means even when the result is zero euros due to exempt operations.
Analysis based on 41 of 44 rulings with a stated position. Updated 17 September 2026.
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