The AI SaaS post-launch checklist: what UK builders actually do in the first 30 days

Shipping the v1 is the easy part. The 30 days after launch decide whether you have a product or a demo. Most UK AI SaaS launches die here — not from bad code, but from neglected ops, missed UK-specific compliance, and founders who go straight from "I shipped" to "I need to build v2" without closing the loop with the first users.

This is a UK-specific post-launch checklist for indie hackers and bootstrapped founders building AI products in 2026. It assumes you shipped with Claude Code, Lovable or Cursor; you're on Vercel or Railway; your backend is Supabase, Neon or Postgres-on-rails; and you're taking payments through Stripe or Polar. Adjust for your stack, but the spine holds.

Day 0 — Launch checklist sanity

Before you announce anything, the literal hour-zero checks:

• Health check endpoint returns 200. curl https://yourapp.com/api/health should be instant.
• Signup works end to end. Open an incognito window, sign up, confirm email, land on the dashboard.
• Payment works end to end. A real £1 test purchase through Stripe or Polar, refund immediately.
• The AI endpoint returns non-empty output. For chat/completion products, post a real prompt and check the response shape.
• Emails arrive from your domain. Welcome email, password reset, receipt. All landing in inbox, not spam.
• Mobile loads and is usable. Not just "responsive" — actually usable on a mid-spec Android in one hand.
• 404 and error pages exist and don't leak. No stack traces in production.

Five of the ten worst UK indie-hacker launches I've watched in the last year failed at least two of these. Check them one more time.

Days 1-3 — Watch the logs, not the launch

Resist the urge to refresh Plausible every ten minutes. The high-leverage work in the first 72 hours is watching the error logs.

• Turn on error monitoring. Sentry, Vercel Analytics, PostHog, Logflare. Pick one, wire it up. Free tiers are sufficient for the first 30 days.
• Watch the AI cost dashboard. Anthropic, OpenAI, Mistral, whoever you route through — the bill can run hot in unexpected ways when real users hit the product.
• Rate-limit your AI endpoints. If you haven't added per-user limits, add them tomorrow. One runaway script can eat a month of AI budget in an hour.
• Set up spend alerts. A £100 alert on your AI provider, a £50 alert on Vercel, a £20 alert on Supabase. These save your week when something runs amok.
• Monitor latency on the AI path. Users tolerate 2-3 seconds; they do not tolerate 10. If you're routing through multiple models, measure each hop.

The common day-2 failure mode is that the product works for the first ten users and falls over at user 50 because nobody tested the load pattern. You want to catch that as a log entry, not as a churn email.

Days 1-7 — Talk to every paying customer

Your first 10-20 paying customers are the most valuable research pool you'll ever have access to. They self-selected into your product with their wallets. Treat them accordingly.

• Send a personal email within 24 hours of their purchase. Not a template, not a drip. A real email from a real address signed by you.
• Ask one question: "What made you buy?" Their answer is your marketing copy.
• Offer a 20-minute call. One in three will accept. Those calls are gold.
• Keep a spreadsheet of every call and the quotes that come out of it.
• Don't pitch. Just listen. You're collecting evidence for the next 30 days of product and copy work.

PMs and founders who build this habit in the first week set the pace for the rest of the year. Those who skip it typically end up guessing at product-market fit from behind a dashboard.

Week 1 — Set up your analytics spine

Without analytics the rest of the checklist is guesswork. Pick a stack and install it:

• Product analytics. PostHog (self-hosted free tier) or Amplitude. Event tracking, funnels, retention cohorts.
• Web analytics. Plausible (UK-friendly, GDPR-compliant), Fathom, or Vercel Analytics.
• Error monitoring. Sentry, free tier is enough for the first 30 days.
• AI observability. LangSmith or LangFuse if you're on LangGraph; OpenAI's built-in dashboards for direct OpenAI; Anthropic console for direct Anthropic. Track prompts, responses and tokens per user.
• Session recording, optional. Microsoft Clarity is free and answers "what are new users actually doing" questions better than any other tool.

Don't install all five at once if you're shipping solo. The highest-ROI two are product analytics and error monitoring. The rest can wait to week two.

Week 1 — UK-specific legal and tax housekeeping

The boring part that gets ignored and comes back to bite. Do this on day 5 or 6, before any of it is urgent.

• Privacy policy and terms. Use a reputable generator (Termly, Iubenda) or a solicitor template. Self-generated is fine for pre-revenue; post-revenue, get the £200 review from a proper solicitor.
• ICO registration. If you process personal data as a data controller, you must register with the Information Commissioner's Office. £40-60/year. Takes 15 minutes. ico.org.uk.
• Cookie banner. Even under the UK GDPR, non-essential cookies need consent. Use a lightweight solution (Cookie Consent by Osano, the built-in tools in Plausible).
• VAT posture. If you're approaching £90,000 of rolling-year UK-taxable turnover, register for VAT now. Monitor monthly — the threshold check is rolling, not annual.
• MTD awareness. From April 2026, self-employed indie hackers with income over £50,000 must file quarterly via Making Tax Digital-compatible software. Xero, FreeAgent or QuickBooks. Set it up when you're comfortably above £4k/month.
• Companies House filings. If you've incorporated a UK company, make sure your confirmation statement date and annual accounts deadlines are calendared. Missing these is the second-biggest own-goal in UK indie hacking.

This block is an hour or two of work that saves you from expensive surprises in month three.

Week 2 — First retention view

Seven days is enough data to start looking at early retention. You're not measuring PMF yet; you're checking the signup-to-second-session conversion.

• Cohort table of day-1, day-3, day-7 return visits by signup week.
• Funnel: signup → first value event. The "first value event" is product-specific (first query run, first document uploaded, first chart rendered).
• Identify the biggest drop-off. That's your top priority for week 3 product work.
• Segment by acquisition channel. Direct vs social vs organic vs referral often have wildly different retention curves.

A rough UK indie-hacker benchmark for B2C AI tools: 30% day-1 return is normal, 50% is strong. Below 15% suggests the activation flow is broken or the value prop doesn't match the product.

Week 2 — Start the content flywheel

You launched the product. Now give Google something to index.

• Blog post 1: The tutorial that new users most need. Pulled directly from your week-1 support conversations.
• Blog post 2: The comparison post. "X vs Y for [use case] in the UK, 2026." Search intent is high, competition is not.
• Blog post 3: The case study. Even one paying user's story, with permission, beats a generic feature page.
• Open Graph images for every post — AI-generated, consistent style.
• Submit to Google Search Console. Submit your sitemap, request indexing for the blog URLs.
• Cross-post to your email list. Even 50 subscribers is a useful audience.

This is a compounding asset. Three posts a week for eight weeks is twenty-four indexed pages before month three — enough to start seeing consistent organic traffic.

Week 2 — Get on one UK-relevant distribution channel

Not all of them. One.

• Indie Hackers. Launch post, milestones, public build-in-public.
• Hacker News Launch HN. Requires a specific template and moderator approval.
• Product Hunt. Still useful for burst traffic; less useful for retention.
• LinkedIn. Underrated for UK B2B AI tools. 2-3 posts a week from the founder.
• X. Use if you already have an audience. Don't start from zero here in 2026.
• Reddit. UK-specific subs (r/ukstartups, r/UKPersonalFinance, r/legaladviceuk depending on product). Never post the link in the body; answer questions, link sparingly.

Pick one. Show up three times a week. After two weeks, measure whether it's moving the needle. If yes, double down. If not, swap.

Week 3 — First paid acquisition test

Only after you have a retention signal. Paid acquisition into a leaky funnel is setting money on fire.

• £100 budget cap. That's £5-10 a day for two weeks.
• One channel. Google Search is usually the highest-intent for UK SaaS. Meta is reasonable for B2C.
• One landing page per ad group. Measure the full funnel, not just the click.
• Attribution: UTM everything. PostHog or your analytics of choice should see every paid click.
• A clear kill criterion. "If CAC is > £30 after £100 spent, I stop and rethink." Know this before you start.

UK AI SaaS benchmark in 2026: a CAC under £40 for a £12/mo subscription is viable if retention is decent. Above £80 and you need either pricing to rise or retention to improve before scaling spend.

Week 3 — First round of bug fixes and UX tuning

Your week-1 error logs and user calls gave you a shortlist. Now's the time.

• Top 10 bugs from Sentry. Crush them.
• Top 3 friction points from user calls. Rework them.
• Dead-click analysis from Microsoft Clarity. Fix the UI cues for features people are trying to click but can't.
• Email deliverability audit. If your welcome email is landing in Gmail spam, nothing else you do matters. Fix SPF, DKIM, DMARC.
• Mobile performance. Lighthouse score, mobile-specific tests, viewport meta tag correctness.

This is the week you go from "it works" to "it feels polished". You don't need new features; you need fewer surprises.

Week 4 — Decide the next 30 days

By day 30 you should have enough signal to answer four questions:

1. Is retention high enough to scale? If yes, push acquisition. If no, push retention work.
2. Which channel is working? Double down on the one that is. Kill the ones that aren't.
3. What's the most confused user touchpoint? Fix it as priority one of month two.
4. What's the next £100 of spend? Paid ads, a freelancer for onboarding copy, a designer, better hosting. Decide.

Write this down in a public (or at least team-visible) doc. A founder who writes down "here's what I'll learn in the next 30 days" ships twice as fast as one who doesn't.

Things to avoid in the first 30 days

• Rebuilding the landing page. Unless conversion is below 1% and you've tested copy, don't touch the structure.
• Adding a second AI model to the router. Single model, single provider, single contract until you have enough load to justify the complexity.
• Hiring. No. Not for 90 days minimum. You don't know enough yet to write the job spec.
• Building the mobile app. If the web app doesn't have 30% day-7 retention, the native app won't either.
• Enterprise features. Until you have 10+ paying SMB customers, enterprise is a distraction.
• Going to conferences. Not in the first 30 days. Your customers are in their inbox, not in a hotel ballroom.

A realistic monthly spend for a solo UK AI SaaS in month one

Line	Typical cost
Hosting (Vercel + Supabase / Railway)	£25-50
AI provider (Anthropic / OpenAI / Mistral)	£30-200 depending on usage
Domain	£1-2 (prorated)
Email (Resend, Postmark)	£0-15
Analytics stack	£0 (free tiers)
Error monitoring	£0 (Sentry free)
Payments fees	~2-5% of revenue
ICO registration (annual, pro-rated)	£4/mo
Claude Code / Cursor	£17-85
Marketing spend	£100 (week 3)
Legal templates	£0-200 one-off

Total in month one: ~£200-600 excluding revenue-based payment fees. This is a solo bootstrapped build, not a VC budget. The trick is to keep the fixed costs low enough that 20 paying customers at £12/mo covers them, and scale from there.

The mindset shift

The hardest transition at 30 days is the one from "I'm shipping" to "I'm operating". A product that exists and has users is now a system. Your job widens: product, marketing, support, ops, compliance, observability. None of these individual boxes is hard; managing all of them on 4 hours a day is.

Three habits that make this bearable:

1. A weekly review. One hour every Friday. Read the logs, read the emails, read the dashboards, write the retro.
2. A kill list. Maintain a "things I will not do this month" list. As important as the todo list.
3. A customer conversation a week. Non-negotiable. You don't get to say "I've been too busy" for this.

The UK indie hackers who go from launch to £10k MRR inside the year almost all share these three habits. The ones who don't mostly stall at £500-1k MRR.

Frequently asked questions

Does this checklist apply to a purely B2B product? Mostly. The UK legal/tax section stays identical. Distribution channels shift (LinkedIn, cold email and partnerships over Reddit and Product Hunt). Retention metrics look at weekly active seats rather than individual day-7 returns.

Do I need to incorporate before month one? No. Sole trader is fine for pre-revenue and early revenue. Incorporate when you start approaching the VAT threshold or when you bring on a co-founder.

Is a mobile app ever justified in the first 30 days? Almost never. If you launched as a mobile app, fine. If you launched web and the question is "should I add iOS", the answer is "not yet".

What about an Android app? Same answer. 98% of UK SaaS success stories run on web for the first 12 months. Mobile is a month-12 decision, not a month-1 one.

How much should I worry about SEO in the first 30 days? Set the plumbing: sitemap, robots.txt, OG images, canonical tags, schema markup on blog posts. Don't obsess over ranking. The SEO return window for a new domain is 90-180 days; month-one work is the foundation.

Key takeaways

• The 30 days after launch decide whether you have a product or a demo. Operations, compliance and retention matter more than shipping features.
• Watch the logs in week one; talk to every customer in week one; tune the analytics in week two.
• UK specifics: ICO registration, MTD awareness, VAT threshold monitoring, cookie consent. Sort these in week one, not month three.
• Start the content flywheel at week two, one distribution channel at week two, first paid test at week three with a kill criterion.
• The transition from "shipping" to "operating" is the hardest mental shift. Weekly review, explicit kill list, customer conversation every week.

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