ChatGPT dates its own list of local businesses: October 2023

Short answer: ChatGPT often tells you how old its list is, and it is old. Asked for the best accountants, plumbers or wedding photographers in 63 cities in six countries, ChatGPT (gpt-4o-mini, through its API, without web search) dates its own answer in 354 of 2,183 answers: "as of my last knowledge update in October 2023". When it gives a year, it is 2023 in 219 answers and 2021 in 16. Gemini dates its answer 5 times in 2,182; Perplexity, which searches the web, never. We asked these questions between July and October 2026. By the engine's own account, the list it presents as the best in town describes what was written about three years earlier.

The answer says "the best in town". It also says when it last looked.

What was measured

All of our studies asked in English: the United States (collected September 13, 2026), the United Kingdom (July 31) and Canada, Australia, New Zealand and Singapore (October 16). The same buyer questions ("What are the best accountants in Calgary?") were put to ChatGPT (gpt-4o-mini) and Gemini through their APIs, without web search and without any location, in 18 to 20 trades and 6 to 13 cities per country; the British study also asked Perplexity, which searches the web. In each answer we looked for a sentence that dates the answer itself: "as of my last update", "as of my last knowledge update in October 2023", "knowledge cutoff", "based on information available up to October 2023", "as of 2024". The detector was first tested on phrases it must catch and on phrases it must leave alone, such as "serving the city since 2023", "established in 2021" or "opened in October 2023", which date a business, not the answer. The year was read in the dating sentence itself. We also counted the answers that say they cannot give "real-time" recommendations, and read 25 of them drawn at random: all 25 are that warning. We looked at that warning on September 27, on our American study alone: it says it cannot recommend, then names eight businesses.

One model, two dates, and a list three years old

ChatGPT does not hide it. In Dallas, its list of accountants is given "based on their reputation and services offered as of my last knowledge update in October 2023"; in Seattle, its electricians come "based on information available up to October 2023". The date is not stable: in Adelaide it writes "due to my knowledge cutoff in October 2021", and in Calgary, Bristol and Wellington it opens with "As of my last knowledge update in October 2021". The same model, asked in the same weeks, gives itself two different dates, two years apart. Most of the time it says nothing about a date, and in 1,333 of its 2,183 answers (61%) it says it cannot give real-time recommendations, then gives names anyway. Gemini almost never dates its answer (5 times in 2,182), and Perplexity, which reads the web before it answers, never did in 488 answers. The date ChatGPT gives is its own statement about its knowledge, not something we can check. But it is the statement a customer reads, next to the names.

What it means if you are the business

If your business opened, moved, changed its name or changed hands after 2023, an assistant answering from memory has, by its own account, never read about it. Two things follow. If you were renamed, keep the old name findable next to the new one ("formerly Smith & Co") on your site and your profiles, because the model may still know only the old one. And make sure the engines that read the web can find you: Perplexity, or ChatGPT when it searches, cite pages they can read, so the name, the city and what you do should be written in plain text on yours. Then ask the question both ways, with search and without, and compare what comes back. Nothing here guarantees being named.

What this does not prove

• These are the models' answers through their APIs, without web search and without the user's location: the way our audit asks. ChatGPT with search switched on answers differently and reads current pages.
• The date is the model's own statement, and it is inconsistent (2023 or 2021). We report what it says, not what it knows.
• A dated answer is not proven out of date: we did not check whether the businesses it names have closed or moved.
• Our detector catches the usual phrasings; an answer dated in other words is missed, so 354 is a floor.
• The collections span July to October 2026, one pass per question.