Confidentiality Agreement Under § 62a StBerG: What the Contract With an AI Vendor Must Say

An AI tool that works with client data needs a contract with specific content. The Federal Chamber of Tax Advisors (Bundessteuerberaterkammer, BStBK) applies § 62a of the Tax Advisory Act (StBerG) expressly to AI vendors and speaks of a confidentiality agreement (Verschwiegenheitsvereinbarung). This article shows what it must contain and how it relates to the data processing agreement. The overall framework is described in the guide AI in German tax firms.

Why are standard software terms not enough?

Because the statute prescribes content that an ordinary software contract does not have to include. An AI vendor is not a forbidden third party: § 203(3) of the Criminal Code (StGB) permits disclosure to persons who contribute to the professional's work, as far as that is necessary, and § 62a(1) StBerG correspondingly allows service providers access.

This permission assumes that the firm ensures the duty of secrecy is in place. If it fails to do so and the contributing person discloses a secret without authorisation, § 203(4) sentence 2 no. 1 StGB makes the professional liable to prosecution as well. Individuals at the vendor who disclose a secret without authorisation are themselves liable under sentence 1 of the same provision.

Access does not mean that somebody at the vendor is reading along. According to the guidance of the Federal Bar (Bundesrechtsanwaltskammer, BRAK) on the parallel provision, the possibility of taking note is enough.

What must the contract say?

§ 62a(3) StBerG prescribes three mandatory elements, plus text form. The table adds the points that follow from the other paragraphs and from the GDPR.

The content required by paragraph 3 sentence 2 falls away to the extent that the service provider is already bound to secrecy by law for this service (paragraph 7 sentence 2).

When must the contract be in place, and in what form?

It must be in place before the first access to client data. The BStBK requires AI vendors to be bound "bevor sie Kenntnis von diesen Daten erlangen", meaning before they gain knowledge of this data. That also applies to a pilot, which is why a test phase starts with harmless data.

Under § 126b of the Civil Code (BGB), text form means a readable declaration that names the person making it and is given on a durable medium. A handwritten signature is not part of that. The medium must, however, be able to reproduce the declaration unchanged. So file the version that applied when the contract was concluded instead of relying on a web page that can change.

How does the agreement relate to the data processing agreement?

It complements it, because the two contracts safeguard different things. The data processing agreement (Auftragsverarbeitungsvertrag, AV-Vertrag) under Art. 28 GDPR concerns personal data. The duty of confidentiality covers everything learned in the course of professional work, and under § 203 StGB that includes business and trade secrets. § 62a(8) StBerG confirms that data protection rules remain unaffected.

Both duties can be met in one document. Art. 28(3)(b) GDPR requires that authorised persons have committed themselves to confidentiality. The warning of criminal consequences and the duty to bind further persons in text form are not found there. A data processing agreement without these points is therefore not enough.

What applies to subcontractors and services abroad?

The duty runs through the whole chain. If the vendor does not run the model or infrastructure itself, the contract must settle whether it may bring in further persons and require it to bind them in text form. § 203(4) sentence 2 no. 2 StGB also covers the contributing person who uses another without making sure that person is bound. Ask for the list of companies involved and how the obligation is put into practice there.

If services are performed abroad, § 62a(4) StBerG requires the protection of secrets there to be comparable to Germany, unless the protection of the secrets does not call for this. The BStBK therefore recommends European vendors or data centres in the EU.

When is the client's consent needed as well?

When the service directly serves a single engagement (§ 62a(5) StBerG). According to the BStBK, the firm's general working tools do not fall under this. Whether AI used on a single engagement triggers the provision cannot, in the chamber's words, be answered without doubt. For sensitive client data it therefore advises obtaining consent in advance.

This consent is different from the consent to a recording under § 201 StGB, which is covered in the article May an AI tool transcribe client meetings?. How the duties to inform clients fit together is shown in Do I have to tell clients that I use AI?.

What applies to lawyers and auditors?

The same, under their own provisions. § 43e of the Federal Lawyers' Act (BRAO) and § 50a of the Auditors' Code (WPO) correspond to § 62a StBerG in paragraphs 1 to 8. The BRAK expressly applies § 43e BRAO to vendors of AI solutions.

What if a vendor will not give these commitments?

Then client secrets do not belong in that tool, unless the client consents and expressly waives the requirements (§ 62a(6) StBerG). The BStBK points out that such a contract can be laborious or impossible to obtain, depending on the vendor. Otherwise the options are anonymisation, pseudonymisation or doing without the tool. If the gap only emerges later, the cooperation must end without delay under paragraph 2 sentence 2. Further checks are listed in the article What should I look for when choosing a vendor?.

TaxMeet (Next Intelligence GmbH, Berlin) is designed for § 203 StGB: no meeting bot joins the call, capture runs per participant on the device, and nothing is executed without human approval.