Artificial intelligence for law firms, accountancies and advisory practices
In a professional services firm, AI saves time on documents: searching your own files and precedents, reading invoices and contracts, preparing drafts and handling the client’s first enquiry. It does not replace the professional’s judgement or responsibility, and it demands special care with professional secrecy and data protection.
By Oliver Guirado · Updated on October 28, 2026 · 5 min read
Why AI fits a professional firm and where to be careful
A firm lives on documents: files, contracts, briefs, invoices, notifications and deadlines. A large part of the time goes on searching, reading, comparing and copying data. AI speeds this up with assistants that answer over your own documentation citing the source, extract data from invoices and prepare drafts that the professional reviews.
The delicate point is confidentiality and responsibility: client data is protected by professional secrecy and the GDPR, and an invented answer in a brief can have serious consequences. That is why we work with minimum permissions, controlled data processing and mandatory human review.
AI use cases in professional services firms
Assistant over the firm’s knowledge
Searches files, templates and internal criteria and answers citing the document, respecting permissions by client and by team.
Summarises clauses, spots dates and obligations and compares versions; the lawyer validates every point.
Client invoices and documents
Reading of invoices, receipts and supporting documents for accountancies and advisory practices, with validation and delivery to the accounting software.
Due-date alerts and a summary of the status of each file.
Sample AI projects in professional services firms
Sample project · Law firm
Internal knowledge assistant for a law firm
Problem
Years of briefs, reports and criteria spread across folders and emails; finding the firm’s own precedent meant asking the most senior colleagues.
Solution
An assistant that indexes the firm’s documentation with permissions by team and by client, answers citing the document and warns when it finds no support. It does not generate new doctrine and does not replace searching the official sources.
Steps
Inventory of sources and confidentiality rules by client.
Preparation and text extraction, with OCR where needed.
Evaluation with real queries written by the lawyers.
Deployment on the firm’s infrastructure and query logging.
Target outcome
Less time searching, knowledge accessible to the whole team and traceability of every answer.
Technology
RAG with permissions, OCR, language model with controlled data processing, audit log.
Sample project · Accountancy and advisory
Invoice reading and posting for an accountancy
Problem
Hundreds of client invoices and receipts arrived in different formats and were keyed by hand into the accounting software, with errors and bottlenecks at quarter-end.
Solution
A flow that receives the documents, extracts the data with OCR and AI, validates supplier, amounts and taxes and leaves them ready to post or in a review queue with the reason.
Steps
Sample of real documents from several clients and accounting rules.
Extraction and measurement of accuracy per field.
Integration with the accounting software.
Review panel and rollout client by client.
Target outcome
Less manual entry, smoother closes and traceability of every figure to its document.
The projects on this page are illustrative, anonymised examples of how we approach this kind of work. Every real project is defined with your information, your systems and your goals.
Data, integrations and compliance
Professional secrecy and confidentiality: client data isolated by file, role-based access and agreements with each provider.
GDPR: legal basis, minimisation, query logging and, where relevant, processing in the EU or on your own infrastructure.
Invented answers: the system always cites the source, acknowledges when it does not know and does not replace consulting official legislation and case law.
Responsibility: every draft is reviewed and signed by a professional.
Define which documents can be used and under which confidentiality rules.
Start with internal search or invoice reading, with controlled risk.
Measure time saved and errors in a pilot team.
Add drafts and intake with mandatory review and clear limits.
Reference prices for AI in professional services firms
What is usually implemented first
Indicative investment
Typical timeline
Internal knowledge assistant with permissions
€12,000 – €40,000
2 – 4 months
Invoice reading and validation with accounting integration
€10,000 – €30,000
6 – 12 weeks
Intake and first-reply assistant
€6,000 – €20,000
4 – 8 weeks
Indicative reference prices in euros, excluding VAT, for projects in Spain and Europe in 2026. The final amount depends on scope, integrations and data quality; we confirm it with a fixed quote after a first meeting.
Can a lawyer use AI without breaching professional secrecy?
Yes, with safeguards: controlled data processing, agreements with providers, data in the EU or on your infrastructure, role-based access and human review. It should be confirmed against the applicable ethics and data protection rules.
Can AI draft legal documents?
It can prepare drafts from your templates, but the professional must review and sign them; a generated text can contain errors or non-existent citations.
How much does a knowledge assistant for a firm cost?
Between €12,000 and €40,000 depending on document volume, permissions and the security required. These are reference prices excluding VAT.
Does it work for accountancies and advisory practices?
Yes, above all for reading invoices and supporting documents, validating them and sending them to the accounting software, and for answering clients’ frequent questions.
Does it cite sources?
Yes: every answer points to the document and section, and the system acknowledges when it finds no support.
Shall we talk about your project?
Tell us about your case and we will reply within 24-48 hours with a proposed scope and an indicative quote.
