Agentic commerce means purchases handled by AI agents instead of people. The customer says what they want ("trail running shoes, size 9, under £130, delivered by Friday") and the agent searches, compares, chooses and in some cases pays.
McKinsey describes it as a model in which agents anticipate needs, compare, negotiate and complete transactions on their own. It distinguishes three patterns: the agent uses the shop's website the way a person would, the agent talks to another agent run by the shop, or a platform acts as the intermediary.
For a UK online shop the practical question is simple: which parts of this already work here, and what is worth preparing now. The short answer is that in the UK, at the end of September 2026, checkout inside AI assistants isn't live yet, but card payments made by agents have started with UK banks, and the agents that visit online shops to compare products are already here.
How an agent makes a purchase
There are four steps:
- Intent. The user writes a request in plain language, with a spending limit and preferences.
- Search and comparison. The agent queries catalogues, product feeds, web pages and reviews. Very often it visits the product pages just as a browser would.
- Choice. The agent proposes one or more options and explains why.
- Payment. Here there are two routes: the agent sends the user to the shop's website to finish, or it pays directly with delegated credentials and preset limits.
The fourth step is the one that needs new protocols, because the card network has to know that the payer is an authorised agent and not a fraudster.
The protocols: ACP, UCP, AP2 and the card networks
ACP (Agentic Commerce Protocol) is the open standard from OpenAI and Stripe, launched on 29 September 2025 alongside Instant Checkout, payment inside ChatGPT. At launch it worked only in the US, with Etsy sellers and more than a million Shopify shops announced. PayPal announced it would adopt ACP in October 2025, and Microsoft uses it for Copilot Checkout, live in the US since January 2026.
In March 2026 OpenAI changed course: according to Retail Gazette, "Instant checkout is transitioning to apps". Users researched products in the chat but bought very little. Today the merchant page says customers complete the purchase on the shop's own site or app, with no fees, and that shopping is live in the US and "will expand to additional regions over time".
UCP (Universal Commerce Protocol) is Google's answer, announced on 11 January 2026 with Shopify, Etsy, Wayfair, Target and Walmart. Its more than 20 backers include Visa, Mastercard, Adyen, American Express and Zalando. It enables checkout inside AI Mode and Gemini with Google Pay. According to the Merchant Center Help Centre, in September 2026 it is available in the US, Canada and Australia, for selected merchants. The UK is not on the list.
AP2 (Agent Payments Protocol) is a Google protocol for payments, unveiled on 16 September 2025 with more than 60 partners. It uses signed "mandates": one records the user's request, another the approved basket. The point is to prove that the agent had permission to buy that item at that price.
Visa and Mastercard have their own programmes, Visa Intelligent Commerce and Mastercard Agent Pay, announced in April 2025. Here Europe, and the UK in particular, is further ahead:
- in March 2026 Mastercard and Santander completed the first end-to-end payment carried out by an AI agent in Europe, announced from London and Madrid;
- on 2 July 2026 Visa announced agentic commerce live in Europe with more than 30 card issuers. Six of them are British: Barclays, HSBC UK, Lloyds Banking Group, Nationwide, NatWest and Vanquis Bank. Every transaction was secured with Visa Payment Passkeys, designed to meet Strong Customer Authentication (SCA) rules;
- on 14 July 2026 Mastercard announced Proto, a sandbox in its Agent Suite where UK retailers can test whether AI agents can find their products and whether their dispute handling holds up. It was due to go live in the UK in August: a testing tool, not a payment service.
What's live in the UK today
At the end of September 2026, according to the official sources:
| Feature | In the UK |
|---|---|
| Google AI Mode (product search and comparison) | Yes, since 28 July 2025 |
| Checkout inside AI Mode or Gemini (UCP) | No, US, Canada and Australia only; the UK is planned "later" |
| ChatGPT shopping with shop feeds | No: the official page lists the US only |
| Copilot Checkout | No, US only |
| Visa and Mastercard agentic payments | Early stage, with six UK issuers in Visa's programme |
| Agentic browsers that visit shops (Comet, Claude in Chrome) | Yes |
The last row matters most today. Agents aren't buying inside chats in the UK yet, but they already visit websites. According to HUMAN Security, in July 2026 e-commerce received 42% of the agentic traffic it measured, and 76% of agent activity was product browsing and search. Akamai counted 47.9% of AI bot traffic on its network going to commerce sites.
The market figures (almost all American)
- Morgan Stanley estimates that agents will handle between $190 billion and $385 billion of US e-commerce by 2030, 10-20% of the total. 23% of Americans say they bought something using AI in the past month.
- Bain goes as far as $300-500 billion, 15-25% of US e-commerce over the same horizon.
- Adobe measured that over the 2025 holiday season traffic from generative AI to US retail sites grew 693% year on year and converted 31% better than other sources (Digital Commerce 360).
- In Europe, according to McKinsey (March 2026), 38% of consumers in France, Germany and the UK already use AI to research products, though the figure isn't broken down by country. For the UK alone, a survey of 1,000 online shoppers by Logica Research for Commerce and PayPal (March-April 2026) found that 21% already use AI tools for online shopping and 64% are interested in trying agentic shopping tools.
These are forecasts and surveys, and the hard numbers are almost all from the US. The cautious reading: agents will influence what people choose well before they do the buying.
What to prepare in your online shop
What you do now serves both today's agents and tomorrow's protocols.
- Product pages that machines can read. Price, availability, variants, sizes and materials written in HTML, not only in images. Complete Product and Offer structured data. Our guide to structured data explains which fields you need.
- Returns and delivery policies stated. Since November 2025 Google has let you declare them with organisation-level structured data (
MerchantReturnPolicy) or in Search Console. An agent that has to meet "delivered by Friday" drops any shop that doesn't state its delivery times. - Merchant Center in good order. It's the way in to UCP when it reaches the UK, and it already feeds Shopping and AI Mode.
- A checkout an agent can complete. Buttons with clear labels, no hidden compulsory steps, errors explained in text. An agent that gets stuck at step three picks another shop.
- Robots.txt and firewall rules that don't block useful agents. Many anti-bot systems treat ChatGPT-User or Claude-User as hostile traffic. OpenAI signs its agent's requests with a
Signature-Agentheader, which Cloudflare and Akamai recognise. The list of bots is in our article on AI crawlers. - A product feed ready for other channels. OpenAI has published the feed specification for ChatGPT. Shopify merchants can distribute their catalogue to agents through Agentic Storefronts, currently aimed at US customers.
Many of these items are the same as good e-commerce SEO. That's why you don't need a separate project: you need to finish the work on your product pages properly.
The impact on SEO and Google Shopping
In the short term the way you work changes little, and who arrives changes a lot. An agent comparing five shops doesn't look at the homepage banner: it reads price, availability, delivery times and reviews. The shops that win are those that state these details clearly and consistently across the website, the feed and Merchant Center.
For Google Ads the signal to watch is Universal Cart, presented at Google Marketing Live 2026. Google said most UCP-powered features would roll out in the US first, then Canada and Australia, "and later the U.K.", with no date for the UK. In the meantime Shopping ads remain the channel where feed data counts most, and campaigns with a clean feed will be the first ready to move to the new formats.
Quick checklist
- Price, availability and variants in the HTML and in the structured data
- Returns policy and delivery times stated on the page and in Search Console
- Merchant Center with no feed errors
- A checkout that can be completed without hidden steps
- AI search bots and signed agents not blocked by the firewall
- Verified reviews visible on product pages
Further reading: SEO for AI agents: how to make your site usable by browsers and agents.
FAQs
It's a way of buying in which an AI agent searches for, compares and buys products on the customer's behalf, within spending limits and preferences set by the user. Payment can happen on the shop's website or directly through dedicated protocols.
Not as of September 2026. Checkout inside AI Mode and Gemini is live only in the US, Canada and Australia, with the UK planned later, and OpenAI lists ChatGPT shopping as live in the US. In Europe the first agentic card payments have started with Visa and Mastercard, including six UK issuers in Visa's programme.
ACP is the OpenAI and Stripe protocol, also used by Microsoft Copilot and PayPal. UCP is Google's, developed with Shopify, Walmart and other retailers, and used for checkout in AI Mode and Gemini. Both are there to let agents and shops talk to each other.
Make product pages readable by machines, state returns and delivery terms, keep Merchant Center in order, check that the checkout can be completed, and make sure the firewall and robots.txt don't block useful agents.
