The symptom that looks like a ranking bug
You type your money keyword into Google and there you are, page one. A colleague in Manchester runs the exact same query, screenshots it, and you're gone. Same keyword, same site, same afternoon. Two different Googles.
Nothing's broken. Google is doing what it was built to do: hand back a result set shaped by where the searcher sits and what language they use. Your rank checker, parked on a US IP with US parameters baked in, only ever shows you one of those two Googles. So you go hunting for a UK problem you literally cannot see on your own screen.
Before you touch a single title tag, look at the right SERP. A geo-targeted Google URL is built from three inputs: gl, the country code; hl, the interface language; and uule, an encoded canonical location string. Change those and you change the search Google actually runs. That's the gap between debugging your UK rankings and debugging a screenshot of your US rankings doing a bad British accent.
Google runs a different search per country
Same query, different countries, different pages. Documented behaviour, not a glitch. Google says outright that results can differ by the searcher's location and language, which means "the ranking" for a keyword is a fiction. There are as many rankings as there are location-language pairs. I went deeper on that idea in why your keyword has no single Google ranking.
For a US-versus-UK gap, three mechanisms usually explain most of what you're staring at. They don't carry equal weight and they don't all apply to every site, so run them as a checklist, not a leaderboard.
Mechanism one: you never told Google the UK page exists
This is the one I hit most often with publisher sites. You've got one page. It ranks in the US because your links, your traffic history, and your hosting all read as North American. In the UK that same page is up against sites Google reads as local, and it loses.
If you do have separate US and UK pages, /en-us/ and /en-gb/ say, and Google still serves the wrong one to the wrong country, you're missing hreflang. The hreflang annotation tells Google that two pages are the same content pointed at different regions or languages, so it can serve the right one to the right searcher. Skip it and Google guesses. It guesses wrong plenty, and it loves to fold your near-identical English pages together and crown one winner, usually the one with the stronger existing signals. For a US-first site, that's the US page.
Two things people botch here. First, hreflang is a suggestion about which version to show, not a ranking boost. A correctly annotated UK page still has to earn its slot. Second, the annotations have to be reciprocal. If your US page points to the UK page, the UK page has to point back, or Google throws out the whole set.
Mechanism two: your domain sends a US signal you can't override with a tag
A .com on US hosting with a US-heavy backlink profile is a loud country signal. A country-code top-level domain like .co.uk is louder, pointing the other way. A ccTLD is about the strongest geographic signal a site can send, and it's basically welded to that country.
This is where a lot of international-SEO regret lives. If you picked .com for everything and now you want the UK, you can't bolt on a ccTLD without a migration. What you can do: set a country target for a subdirectory or subdomain, run hreflang, and earn actual UK links and mentions. But be honest about the slope you're on. You're shoving a US-signalled page uphill into a market where your competitors are .co.uk sites that have been sending the UK signal for years.
For a publisher or affiliate this shows up as a maddening pattern. Your review page owns the US results and prints US commissions. The UK version of the same offer converts fine, when anyone finds it, but the page barely surfaces because every signal Google reads about the site screams American.
Mechanism three: the SERP itself is a different shape in the UK
Rankings aren't only about your page. They're about everything else on the page. The UK SERP for your keyword might be stuffed with a local pack, a different set of shopping ads, or publishers with domestic authority you don't have. You can sit at organic position 4 and still be invisible, because positions one through ten on screen are ads, a map, and People Also Ask before your blue link shows up.
You can't diagnose this from a rank number. A tracker tells you "position 6." It won't tell you that position 6 in the UK sits under a four-pack of local businesses and a shopping carousel that never appear in the US result. The layout is the diagnosis, and the only way to read it is to look at the rendered UK page.
How I actually check this
I stop trusting the number and go look at the page Google serves a UK searcher. Preview both SERPs side by side. Set one to gl=us, hl=en, a US city; the other to gl=gb, hl=en-GB, a UK city. Then read them like two separate documents. That's the whole reason I built anywhereserp to compare two locations: it builds the geo-targeted URL from Google's own Geotargets data, so I'm looking at the real UK result, not a US result in a costume.
The comparison almost always shows that "not ranking in the UK" is three separate findings wearing one label. The wrong page is served (hreflang). The site reads as American (domain and links). Or you do rank, but the UK layout buries you (SERP shape). Each has a different fix, and no rank-tracking spreadsheet on earth will tell them apart.
The diagnosis lives in the SERP, not in the report about the SERP. A US position and a UK position for the same keyword are two measurements of two different searches. Look at both rendered pages instead of one aggregated number and the "bug" resolves into a specific, fixable cause.