Taco Bell's AI took orders at 500+ drive-thrus. Someone ordered 18,000 waters.

From the archive. First reported by The Wall Street Journal, August 2025. Where it stands now: Scaled up, as of October 2026, Fortune, Oct. 14, 2026. Why I saved this: Two million orders processed, yet the moments that spread were an order for 18,000 waters and the AI asking a customer who'd just ordered a large Mountain Dew what he'd like to drink. A year after promising hundreds of stores, Taco Bell's tech chief said the chain was rethinking where the AI should take orders.

Previously

In July 2024, Yum! Brands said its drive-thru voice AI was live at more than 100 Taco Bells in 13 states and would reach hundreds by year-end. It promised easier shifts, better accuracy and shorter waits, but published no results and didn't name a vendor.

August 2025 — Taco Bell's voice AI now runs at more than 500 drive-thrus, per the WSJ. Now its tech chief says the AI shouldn't take every order everywhere. Here's what changed since Part 1 (July 2024), what it cost, and what went wrong.

Cost and outcome (as of August 2025)

Footprint: More than 500 US drive-thrus, per the WSJ. (The Verge)
Orders handled: Two million processed successfully since launch, Taco Bell says. (BBC)
Most-viewed failure: An Instagram clip of the AI asking a customer who ordered a large Mountain Dew what he'd like to drink, viewed more than 21.5 million times. (BBC)
Cost, accuracy, intervention rates: Not disclosed.

What the tech chief said

Mathews was frank. "We're learning a lot, I'm going to be honest with you," he told the WSJ, according to The Verge. "I think like everybody, sometimes it lets me down, but sometimes it really surprises me."

The company still plans to push ahead with voice AI and evaluate the data, The Verge reported. But Mathews said using the AI exclusively at "super busy restaurants with long lines" might not be a good idea.

The new approach is coaching, not removal. "For our teams, we'll help coach them: at your restaurant, at these times, we recommend you use voice AI or recommend that you actually really monitor voice AI and jump in as necessary," he said, as quoted by TechCrunch. TechCrunch reported that franchisees appear to have leeway to run it their own way.

What went wrong at the speaker

Two kinds of failure went viral. The first was trolling. In one clip, a customer ordered 18,000 water cups, which the BBC said seemingly crashed the system. TechCrunch reported the aim was to "bypass" the AI and reach a human. The second was plain error: the Mountain Dew loop, where the AI kept asking for a drink the customer had already ordered.

Both point at the same gap. A human order-taker can tell a prank from a real order and knows when to stop upselling. The AI, in these clips, couldn't do either.

It's not just Taco Bell

McDonald's withdrew AI from its own drive-thrus the previous year after misheard orders, the BBC noted, including bacon added to ice cream and hundreds of dollars of chicken nuggets added by mistake. McDonald's, Wendy's and White Castle are all experimenting with drive-thru AI, The Verge reported.

Why it matters for operators

Mathews's plan amounts to deciding, store by store and hour by hour, when the AI takes orders and when a person listens in or takes over. That keeps a crew member tied to the headset at busy times, which cuts into the labor savings the rollout was meant to bring. The trade-off is fewer bad orders at the moments they're most costly.

What's changed

The rollout reached more than 500 stores, per the WSJ, up from more than 100 in July 2024. We don't know the end-2024 count Yum was aiming at. The pitch changed from AI taking the order to AI taking the order when it's quiet enough to work.

What went wrong

Pranks got through. An 18,000-cup order and a looping drink prompt became public examples.
Busy stores are the weak spot. Taco Bell's own tech chief says peak-time use may not be wise.
Still no published metrics. Two million successful orders is a count, not an accuracy or intervention rate.
What we don't know yet: how many orders needed a person, whether any stores have switched the AI off, and who supplies the system.

Our follow-up question for Taco Bell

Of the more than 500 stores running voice AI, how many now take peak-time orders with a person instead?

Sources

Emma Roth, The Verge, “Taco Bell's AI drive-thru plan gets caught up on trolls and glitches,” Aug. 28, 2025. theverge.com
Shiona McCallum, BBC News, “Taco Bell rethinks AI drive-through after man orders 18,000 waters,” Aug. 29, 2025. bbc.com
Anthony Ha, TechCrunch, “Taco Bell is having second thoughts about relying on AI at the drive-through,” Aug. 30, 2025. techcrunch.com
The Wall Street Journal, “Taco Bell Rethinks Future of Voice AI at the Drive-Through,” Aug. 28, 2025 (paywalled; quoted via sources 1–3). wsj.com
Sasha Rogelberg, Fortune, “Yum! Brands exec pushes back on AI hate: Taco Bell drive-thru bot helped increase employee retention,” Oct. 14, 2026. fortune.com
Earlier in this series: Part 1. /case/taco-bell-voice-ai-expansion

Disclosure: [not in copy] Editor placeholder