Six banks wrote down what shoppers fear about AI agents, and PayPal signed up to Muse within a day

Who does a shopper call when an AI agent buys the wrong thing? Six banks put that question in writing on 22 September 2026. NatWest Group, Bank of America, Capital One, ING Group, Commonwealth Bank of Australia and New Zealand’s ASB Bank published a joint paper, “Building Trust in Agentic Commerce: Customer-centric principles for a trusted and thriving ecosystem” [1]. Reuters, carrying it through Insurance Journal on 23 September, reports the banks’ reading of their customers: people are “not sure whether they will be protected or who they will need to go to”, and worry that agents “may buy the wrong thing” or that they will “lose their money to scams and fraud” [3].

The paper names five principles: transparency, safety, privacy and data, choice, and interoperability [1]. None of them is binding. NatWest says the group will “detail in a subsequent paper how the principles can be implemented” [1], and ING’s version of the announcement invites merchants, technology providers and other financial institutions to help turn the principles into practical standards [2]. Neither release names a date for that second paper, and neither says who carries the loss on a disputed agent purchase [1] [2].

Reuters adds one number from outside the banks. John Lewis told it that searches coming from AI agents had risen to 2.5 per cent of its searches, from 0.3 per cent a year earlier [3]. That counts searches, not purchases, and it is one retailer.

PayPal joined Muse

PayPal said it will support Meta’s Muse agent at checkout. PYMNTS dated the announcement 22 September 2026 [5] and American Banker carried it on 23 September, quoting PayPal: “Soon, PayPal’s hundreds of millions of consumers will be able to shop and check out with Muse across PayPal’s merchants worldwide” [4]. American Banker also notes that Muse runs purchases inside a secure environment that asks the user to approve risky actions such as payments before they happen [4].

PYMNTS found no launch date [5]. Muse launched on 8 September 2026 with Stripe’s Link as its wallet [5], and the 22 September edition of this brief covered Shopify’s Shop Pay tie-up and Amazon’s block. Add PayPal and one agent has three payment partners announced in its first fifteen days. Only Link was working at launch.

Amazon’s own agent, and it asks first

Amazon upgraded Seller Assistant, its agent for third-party sellers, on 23 September 2026 [7]. The post, by Mary Beth Westmoreland, Amazon’s vice-president for worldwide selling partner experience, says sellers accept its recommendations “over 90% of the time” [6]. New always-on workflows watch a seller’s business when nobody is logged in, but “when it takes actions, sellers stay in control, reviewing and approving them before they are carried out” [6]. A new selling partner plugin takes Seller Assistant into Amazon Quick and, in beta for United States sellers, into Anthropic’s Claude, and every primary account holder can claim a free twelve months of Amazon Quick Plus until 31 December 2026 [6] [7]. The Next Web quotes Amazon’s aim that sellers “would never have to log into Seller Central” [7].

Three days after Amazon blocked Meta’s agent from its store, as the 22 September edition reported, it put its own agent inside Anthropic’s Claude. The 90 per cent is Amazon’s figure for its own tool, with no method published beside it.

Nothing on stablecoin rules moved between 23 and 25 September 2026 that this desk could source twice. Treasury’s GENIUS Act comment window still closes on 19 October 2026 [8].

On 22 September six banks wrote that shoppers are not sure who they will need to go to when an agent buys the wrong thing. For a Muse shopper the candidates now include Meta, Stripe, Shopify and PayPal.