Ask three agencies and you will get three evasions, because the honest answer has a shape people dislike: it depends, but on knowable things. Here is the answer with the dependencies made explicit, and real timelines from my own client work.
The honest baseline
For an established site doing sensible work, early movement typically shows in eight to twelve weeks, and results worth celebrating arrive over two to four quarters. SEO compounds; the curve starts shallow and steepens. Anyone promising page one in thirty days is describing either a keyword nobody contests or a method with an expiry date.
What fast actually looks like
Fast is possible when the foundations are right. A banking client of mine went from 2.87 million to 6.36 million impressions in a single quarter, with 40,000 clicks, on a newly launched site. What made that speed possible was not a trick: redirects mapped before launch, technical groundwork done first, and a hundred-plus keywords each given exactly one owner page. The speed was earned in the preparation.
What decides your timeline
Four factors, roughly in order. Your starting authority: an established domain moves faster than a new one. Your competition: “wholesale display fixtures Dallas” and “car insurance UK” are different sports. Your technical health: sites with crawl problems are running with a parachute attached. And execution cadence: SEO done in a burst then abandoned resets its own clock.
The signals that it is working before rankings move
Watch impressions climbing in Search Console, more queries triggering your pages, and average position improving on page-two terms. These lead rankings by weeks, and they are how you distinguish “not working yet” from “not working”. A pet products client of mine showed exactly this pattern on the way from 4,290 impressions to 117,000.
If you are three months into an engagement with none of those signals, that is not patience being tested, that is a question needing an answer. An independent SEO audit is how you get one.