What sources does Taxxa search?

Taxxa searches a continuously updated collection of more than one million pages from tax authorities, government publications, legislation and case law across the European jurisdictions it covers. Every response cites the underlying material, so a professional can inspect the rule, its jurisdiction and whether it is current before relying on the result.

Can Taxxa work with a team’s own documents?

Yes. Research can combine the public knowledge base with a team’s own PDF, DOCX, CSV and TXT files in one workspace. That makes it possible to compare a client document with the relevant guidance, trace a conclusion to its source and prepare a draft without losing the evidence that supports it.

Who is Taxxa built for?

Accountants, auditors, tax advisors, payroll specialists, bookkeepers and advisory teams working across European jurisdictions. Shared workspaces keep research available to colleagues, and citations make review easier.

Where is customer data stored, and is it used to train models?

Customer data stays in the European Union and is never used to train language models.

Does Taxxa replace professional judgement?

No. Taxxa is a research and drafting workspace. It helps professionals reach an informed starting point faster; the professional still reviews the evidence and makes the final decision. It does not file returns, post bookkeeping entries or give legal advice.

United KingdomChartered Institute of Taxation

HMRC pauses agent number checks until 17 November

HMRC has paused ARN checks on helplines until 17 November 2026; from 18 November every employee who contacts HMRC for clients needs access to the firm's 11-character reference.

By Taxxa AI OyPublished 7 October 2026

Tax

HMRC has paused Agent Reference Number checks on its helplines until 17 November 2026TAX, giving tax advisers extra time to prepare. The CIOT reported in September that members calling certain helplines were being asked for their firm's ARN as part of security checks, and advised agents to have the number to hand; HMRC has now confirmed the checks for this purpose are on hold. During the pause HMRC may still ask for an ARN in other circumstances, such as when investigating an issue on an agent's behalf, and existing security, identity and client-authorisation checks continue to apply.

From 18 November 2026 HMRC will resume ARN checks for businesses required to register with HMRC as tax advisersTAX. HMRC advises that every firm employee who interacts with HMRC on behalf of clients should have access to the firm's ARN from that date, so firms need to work out how to share it with the relevant individuals. Agents get three months from the date they are required to register to apply for an Agent Services Account, and may keep interacting with HMRC during those three months and while HMRC considers the application. The date coincides with one of the registration waves under mandatory agent registration: agents that only provide third-party payroll services and do not otherwise interact with HMRC must register from 18 November 2026TAX, following registration opening on 18 May 2026 and the 18 August 2026 start for existing Self-Assessment and Corporation Tax agents without an Agent Services Account. A further wave follows, with financial services organisations required to register from 31 December 2026.

The ARN itself is an 11-character reference on the front page of the firm's Agent Services Account, beginning with four letters including "ARN" followed by seven digits, for example XARN1234567. Agents who applied for registration recently and have not yet received an ARN can give their registration application reference while the application is being processed.

The legal basis is HMRC's mandatory tax adviser registration, which commenced in May 2026, with the ARN requirement on helpline calls to resume for registered businesses from 18 November 2026TAX.

If your firm contacts HMRC on behalf of clients, make sure every employee who does so can access the firm's ARN before 18 November 2026, and use the pause to complete any outstanding tax adviser registration.

Sources

United KingdomChartered Institute of Taxation

HMRC pauses agent number checks until 17 November

HMRC has paused ARN checks on helplines until 17 November 2026; from 18 November every employee who contacts HMRC for clients needs access to the firm's 11-character reference.

By Taxxa AI OyPublished 7 October 2026

Tax

The legal basis is HMRC's mandatory tax adviser registration, which commenced in May 2026, with the ARN requirement on helpline calls to resume for registered businesses from 18 November 2026TAX.