You can run the whole four-role AI system — writer, notetaker, automator, analyst — on free tiers in 2026. Here's how, where free tiers genuinely end, and the settings page that tells you what "free" costs.

The best AI stack for a one-person business costs £0. Read the settings page anyway.

Somewhere along the way "building an AI stack" started to mean "accumulating subscriptions". Founders show off £200/month tool collections the way people once showed off gym memberships — the spend standing in for the results.

Here's the contrarian bit, which is also just the maths: in 2026, free tiers genuinely cover the four-role system for most one-person businesses. Not crippled trials — working free tiers. The constraint on your AI leverage is almost never budget. It's whether the tool gets used weekly.

The decoded idea: roles first, tools second, spend last. Monday's post named the four roles — writer, notetaker, automator, analyst. The £0 stack is those roles on free tiers:

• Writer — every major assistant's free tier handles drafts, edits and summaries daily. Batch your asks (one session, five tasks) and free limits stretch further than you'd think.
• Notetaker — free tiers typically cover a handful of meetings or voice notes a month. For the Sunday voice-note method, that's enough.
• Automator — automation platforms' free plans run a few simple workflows. Pick your two most-repeated admin chains (invoice chase, file sorting) and stop there.
• Analyst — your writer doubles as it: paste the numbers, use Wednesday's weekly-review prompt. A separate analytics subscription is a luxury until the questions get bigger than the free tier.

We won't name a "best" tool per role here, deliberately: leaderboards change monthly and any specific pick would be stale by autumn. The roles don't change. Vet whatever the current candidates are the same way (below) and the system holds whichever logos are on it.

Where free tiers genuinely end. Honesty owed: you'll feel real limits at (a) volume — daily long-form or heavy meeting loads blow through caps; (b) collaboration — free tiers are single-player; (c) integration depth — connecting tools to each other is where paid plans live. The upgrade rule that keeps you honest: a tool earns a subscription only after it's been hitting its free-tier ceiling weekly for a month. Pain first, payment second. Never upgrade on launch-day excitement.

The real price tag. Free often means your data is part of the payment. So the settings page is the price tag — read it before a tool joins the stack: Is your content used for model training, and can you turn that off? What's the retention period? Can you delete your data and export it out? Two minutes per tool. If a "free" tool fails the two-minute check and won't let you opt out, it isn't free — it's just billing you in a currency you can't see.

One caveat to keep this honest: free tiers change without notice, and the caps quoted anywhere (including here) age fast. Check the current limits on the day you build. The system is evergreen; the fine print isn't. And since tools and money met in this post: not financial advice — your spend, your call.

The responsible-AI note. The vet step is this post's practical move: data policy read, training off, retention set — before any tool, free or paid, touches your business. Disclose where AI touches client-facing work regardless of what the tool cost you. Verify outputs the same on free tiers as paid; the price of the tool never changed the error rate.

The one-evening build order. If the stack doesn't exist yet, sequence it like this. Tonight: pick a writer, run the two-minute settings check, and give it one real task — a draft you actually need. This week: add the notetaker and record Sunday's voice note. Next week: your first automation, the single most-repeated admin chain you have, nothing else. Week three: run Wednesday's numbers prompt and the analyst role exists. Four tools, four weeks, £0 — and each one arrived with a job, which is why this stack gets used while the £200/month collections gather invoices. Resist the urge to build it all tonight; a stack assembled in one sitting is a stack abandoned in one month.

The quarterly cull. Free has a hidden cost paid in attention: every tool is a login, an update email, a place your data lives. So once a quarter, ask one question per tool — "did this run in the last two weeks?" No means it leaves the stack (export data, delete account, done). The four-role system stays; the roster earns its place per quarter. A lean stack you trust beats a full one you audit never — and with tools, as with the intern, trust is something you can only maintain over things you can still see all of.

One decoded AI move, every week. Follow @aithebrief on Instagram for the daily version, or subscribe free on Substack for the deep one.