Moving client data across borders is easy to do without noticing, because a tool can sound local and still send data abroad, to a provider's servers or a sub-processor in another country. For a firm holding client information, that is an international transfer, and it carries its own rules.
Know where the data goes
Before you adopt a tool, ask where it processes and stores data, and which sub-processors sit behind it. Many providers operate across several countries, and the answer is rarely on the marketing page.
Use a lawful transfer route
Where data leaves the United Kingdom, you need a lawful basis for the transfer, such as a country covered by a UK adequacy finding, or the UK addendum to the standard contractual clauses. The provider's contract should set this out. If it cannot, the tool is not ready for client data.
Write it down
Record the transfer, the safeguard relied on, and the assessment behind it. It is the same discipline as any other processing, applied to one that happens to cross a border. The wider data duties are in UK GDPR when client data meets AI.
International tools are fine for a UK firm, provided you know where the data travels and you hold the paperwork that makes the journey lawful.
For the mechanics, from adequacy decisions to transfer risk assessments, the ICO's guidance on international transfers is the place to start.
If nobody in your firm can say which countries client data passes through on its way in and out of your tools, that is a mappable problem rather than a standing worry. We chart it with firms in an afternoon, so start with a conversation.