Google Just Made Itself the Cart for Every Shopping Trip on the Internet. Australian Checkout Lands in Months.

Google introduced Universal Cart at I/O 2026. It is a single shopping cart that follows the user across Search, Gemini, YouTube, Gmail and merchant sites. Items added anywhere land in one place. Price drops, restock alerts and compatibility checks all run automatically through Gemini.

The cart is the user-facing layer. Underneath sits the Universal Commerce Protocol (UCP) and an updated Agent Payments Protocol (AP2). UCP is the open standard that lets agents check out across Google surfaces. AP2 is how an agent authorises a payment without the user finishing the transaction themselves.

Rollout starts in the US today. Checkout features arrive at Nike, Sephora, Target, Ulta Beauty, Walmart and Wayfair this summer. Canada and Australia are next. The UK follows after that.

That matters because the cart is where price comparison, payment and ownership of the buying intent all collapse together. If Google owns the cart, Google owns the moment of conversion no matter which retailer wins the sale.

Australian retailers spent the last decade optimising checkout on their own domain. Universal Cart breaks that model. A shopper might add an item on your product page, switch to Gemini to compare it against alternatives and complete the purchase from a Google surface. Your conversion happens off-site. Your data lives somewhere else.

For paid media, this is the agentic shopping graph going live. Performance Max already buys media on intent signals you do not see. UCP and AP2 extend that opacity to the cart and the payment step.

Universal Cart is the clearest signal yet that the merchant page is no longer the front door for commerce. The retailers that will keep margin are the ones who fight to own the post-purchase relationship, not the search box.