What is an AI agent? A plain-English guide for UK businesses
What AI agents are, how they differ from ordinary automation, when they are worth it, and how many UK businesses are already using AI.
Published · Updated · By the TrustedAIAgencies editorial team
“AI agent” is one of the most used, and least defined, terms in business technology. Here is a plain-English explanation.
The short answer
An AI agent is software that uses an AI language model to work towards a goal by deciding its own next steps: which information to look up, which tool to use, and when it is finished.
That is different from an automated workflow, where a person designs the steps in advance (“when a form is submitted, add the contact to the CRM, then send this email”).
Anthropic, the AI company behind Claude, draws the same line in its widely cited guide Building effective agents: workflows orchestrate models and tools through predefined code paths, while agents dynamically direct their own processes and tool usage.
A simple example
Workflow: a customer emails an invoice. The system extracts the amount and supplier, adds them to your accounting software, and notifies finance. Every step is fixed.
Agent: a customer emails asking why their order is late. The agent looks up the order, checks the courier’s tracking, sees a delay, drafts an apology with a new delivery date, and asks a person to approve a goodwill discount. The steps depend on what it finds.
When are agents worth it?
Anthropic’s advice is to find the simplest solution possible and only add complexity when needed. Agents trade higher cost and slower responses for flexibility, and their errors can compound over several steps. In practice:
- Use a workflow when the steps are known and repeatable: data entry, notifications, syncing systems, routine reports.
- Consider an agent when the task is open-ended: triaging varied customer requests, researching, or handling multi-step support cases.
- Keep a person in the loop for anything that affects customers, money or decisions about people.
How many UK businesses use AI?
The Office for National Statistics asks UK businesses about AI in its Business Insights and Conditions Survey. In late March 2026:
- 26% of businesses reported using at least one type of AI technology, up 8 percentage points from late March 2025;
- 45% of businesses with 250 or more employees did so;
- 18% said they planned to adopt at least one type of AI technology in the next three months, the highest since the question was introduced in late September 2023.
The ONS describes these as official statistics in development, so treat them with appropriate caution.
Questions to ask an agency about an AI agent
- What can the agent do on its own, and what needs approval?
- How is it tested, and how do you measure accuracy?
- What happens when it is unsure?
- What does it cost to run each month, including model usage?
- Where is our data sent?
Looking for help? Browse UK agencies that build AI agents, read how to choose an agency, or get matched for free.