Best software for law and accountancy firms compared

Tool	Who it is for	Limits	Price
Plea	Law firms and court procurators, from one person to several professionals	The basic plan only invoices and includes no AI; add-ons and AI depend on the plan	From €19.90 a month; €49 per professional a month on Essential; excluding VAT Source, accessed on 10 October 2026.
Kleos	Law firms that want cloud management with LexNET and time tracking	Priced per user; expandable storage has an additional cost	€49, €65 or €79 per user a month; the page does not state VAT Source, accessed on 10 October 2026.
a3asesor	Accountancy firms that want software for the employment, tax, accounting and management areas	A family of programs by area; the page does not publish prices	Not stated: the page refers you to request information Source, accessed on 10 October 2026.
BAI Business	Small law and accountancy firms that want customers, documents, tasks and invoices on one platform	General platform for small businesses; its sheets do not describe procedural deadlines or a LexNET connection	Depends on the plan; explained in a conversation

For a law firm, Plea and Kleos offer case-file and deadline management, priced per professional or per user; for an accountancy firm, a3asesor covers the employment, tax and accounting areas. A general platform such as BAI works if you put customers, documents and invoices first.

Reviewed on 2026-10-10. BAI Business is one of the tools compared and publishes this article. In the table, BAI appears as "depends on the plan": it is explained in a conversation.

The criteria we compare by

• Case files and customers. One record per customer and one case file per matter, with the parties involved and an alert for possible conflicts of interest.
• Deadlines and communications. A calendar of deadlines with alerts, with the count of non-working days for court deadlines, and connection with the court's communications.
• Documents, time and billing. Documents per case file with templates, time recording, fee notes and invoices with the verifiable invoicing system.
• Professional secrecy and data. Permissions per case file, access log and a data processing agreement with the provider.
• Who it is designed for. Whether the program is for lawyers, for accountancy firms or general, and whether it suits a one-person firm or several.
• Price, users and exit. What the fee includes, how many users it covers and how you take your data with you if you leave. The tests to check it are in the downloadable guide for law and accountancy firms (PDF, in Spanish).

The tools

Plea

Plea is a program for law firms and court procurators (procuradores) with four plans. The basic one is for one person who only invoices and does not include artificial intelligence: invoices, fee notes and corrective invoices with Verifactu, quotes, engagement letters, payment with a payment link and customers with their history. From the Essential plan it adds case files with parties, deadlines, documents, hours and fee notes, a work inbox with owner and date, templates, a diary with deadlines and the court's non-working days, online appointments with payment and integrations at no cost. The Complete plan includes all the add-ons and more artificial intelligence, and the Firm plan adds a management dashboard and set-up with a person.

Its page publishes the price of each plan: €19.90 a month the basic one, €49 per professional a month the Essential, €149 the Complete and from €129 per professional in Firm, all excluding VAT, with no minimum term and with a 14-day trial; team staff cost €25 a month (source: Plea, accessed on 2026-10-10).

It suits law firms and court procurators, from one person to a team, that want case files, deadlines and invoicing in a single program. It is worth looking at which add-ons you need, because the fee rises with them, and asking how data is exported if you leave, which the page does not detail.

Kleos

Kleos, from Wolters Kluwer, is cloud-based software for law firms, focused according to its page on simplicity, security and mobility. It brings together management of case files, time, documents and email, reports and invoicing, with a mobile app, an API and integrations with Outlook, Stripe and Verifactu, and an artificial intelligence function, Kleos Expert AI. Its entry plan includes a direct connection with LexNET to send documentation and receive the court's notifications, task and deadline management, time tracking and add-ins for Word and Outlook. It declares certification to the ISO 27001 and 22301 standards.

The plans cost €49, €65 and €79 per user a month, with an offer on the higher plan at €69; the entry plan includes 15 GB of cloud and expandable storage has an additional cost, and the page does not say whether the prices include VAT (source: Kleos, accessed on 2026-10-10).

It suits firms that want to communicate with the courts from the program itself and value security certification. The price is per user, so the cost grows with the team, and the AI, advanced invoicing and single sign-on are only in the higher plans.

a3asesor

a3asesor is Wolters Kluwer's software for accountancy firms. Its page presents it as the software that covers all areas of the business, employment, tax, accounting and management, with access to customer information from a single point. It is a family of programs organised by area: accounting, with products such as a3asesor Eco, Bank and a3factura; tax, with a3asesor Ren, a3asesor Soc and a3BOEFiscal; employment, with a3asesor Nom, a3HRgo and a3convenios; and firm management, with a3asesor Ges and a3innuva Doc, as well as an electronic notifications portal and training services for accountancy firms.

The page does not publish prices and refers you to request information (source: a3asesor, accessed on 2026-10-10).

It suits accountancy firms that need payroll, tax and accounting programs of their own line of work, and that already work with Wolters Kluwer's tools. Since there are several products per area, you have to ask for a quote covering what you need and check in writing what is charged for each one, because there is no single published price.

Where BAI fits and where it doesn't

BAI Business is a management platform for the self-employed and small businesses: CRM, website, visibility on Google, AI receptionist, appointments, invoicing and team. For a law or accountancy firm, according to its solution sheets, it includes a record per customer with its history; enquiries that are assigned to whoever handles each subject and alert the person responsible if nobody replies; document templates created from your own models with simple electronic signature and a trail of each signature; boards with tasks, owner, date and an alert before the deadline, with time tracking and billable hours; invoices from the customer's record; and a link so each customer can follow the status of their own matter.

It fits if your firm mainly needs to organise customers, documents, tasks and invoices in one place, with website and visibility. It doesn't fit if you need a specific legal program: its sheets do not describe a calculation of procedural deadlines or connection with LexNET, and its electronic signature is the simple one; if a document requires an advanced or qualified signature, BAI does not present it as such. For those cases, a program such as Plea or Kleos may cover it better. You can run the ten criteria in the downloadable guide (PDF, in Spanish) against any program, ours included, and see BAI on the page for law and accountancy firms.

How we checked this

We read the official pricing or product page of each provider on 2026-10-10 and noted only what is stated on it; what is not stated is said so or not written. We compare programs with the same purpose and with essential, relevant and verifiable features, with no judgements about any brand, as Spain's Unfair Competition Act (Ley de Competencia Desleal) requires for comparative advertising. Prices change: each figure carries its date and the page is reviewed every ninety days, or sooner if a price changes. BAI Business is one of the tools compared and publishes this article.

Frequently asked questions

Which program should I choose for a small law firm?

It depends on whether you need full legal management, with deadlines and communication with the courts, or a general platform with customers, documents and invoices. The table summarises who each program is for and what it doesn't do.

And for a tax and employment advisory firm?

An advisory firm needs above all software for the accounting, tax and employment areas. The programs specific to advisory firms are published by providers that usually ask you to get in touch to give a price; the table says when it is not stated.

How much does a program for a firm cost?

It depends on the number of professionals and the add-ons. The table gives what each provider publishes, with the date it was accessed; check it before signing up because it changes.

What must a firm's program comply with on professional secrecy and data?

It must allow permissions per case file, log accesses and sign a data processing agreement with the provider. The downloadable guide sets this out with its official source.

Sources

• Plea pricing, accessed on 10 October 2026.
• Kleos pricing plans, accessed on 10 October 2026.
• a3asesor software for accountancy firms, accessed on 10 October 2026.