The first 90 days after buying a startup: a practical plan

In the first 90 days after buying a startup, your job is to secure control, protect revenue and learn how the business really works before you change anything big. Spend days 1 to 7 locking down accounts, days 8 to 30 stabilizing and listening, days 31 to 60 fixing the obvious problems, and days 61 to 90 making your first growth bets.

This is general education, not legal or financial advice. Adapt the plan to your business and get professional help where needed.

Before day 1: closing checklist

Your first 90 days start well only if closing was clean. Before you consider the deal done, confirm that you have:

• A signed purchase agreement, with warranties, a non-compete and a transition period.
• Funds released through escrow only after the transfer items were confirmed.
• A written list of every asset and account, with who held it and who holds it now.
• Signed IP assignments for code, designs and brand assets.

If you have not yet done due diligence, go back to the due diligence checklist. If you skipped verifying revenue, see verified revenue versus screenshots.

Days 1 to 7: secure everything

Change every credential

The seller, former contractors and tools that were connected to the business may still hold passwords and keys. On day one:

• Reset passwords and enable two-factor authentication on the domain registrar, DNS, hosting, code repository, email, payment provider and analytics.
• Rotate API keys and secrets, including keys for AI model providers, email services and databases.
• Remove access for people who no longer need it.
• Move accounts to your own email addresses.

Stripe recommends using restricted API keys rather than full secret keys so that each service gets only the permissions it needs, and says to create a separate key for each service. Stripe's guide on restricted API keys walks through how to do that and how to retire an old key safely. The same least-privilege thinking applies to every other account.

Back up everything

Take a full copy of the code, databases, uploaded files, configuration and documentation. Test that you can restore it, or at least that the files open.

Confirm money flows

Check that payouts from the payment provider reach your bank account, that subscription renewals are running and that failed payment emails still go out. A silent billing problem in week one can cost more than any feature.

Write down who to call

Make a list of vendors, support contacts and anyone who knows how a system works. Keep it in a shared document.

Days 8 to 30: stabilize and learn

Keep the seller close

Use the transition period you negotiated. Schedule short regular calls, and ask the seller to walk you through support, releases, billing problems and anything fragile. Record the sessions if the seller agrees.

Introduce yourself to customers

Send a short, honest message to customers. Say that the product has a new owner, that service continues, how to reach you and what will not change. Do not announce major changes yet. A clear note reduces surprise cancellations.

Answer support yourself

Read every ticket for the first few weeks. It tells you more about the product than any dashboard. Note the top ten recurring questions and complaints.

Learn the numbers

Build a simple weekly dashboard with:

• New customers, cancellations and net revenue
• Monthly recurring revenue, plus any one-time revenue
• Refunds and failed payments
• Support volume
• Costs, including hosting and AI usage

Compare with what the seller reported. FE International's checklist describes the benchmarks buyers commonly test, including net revenue retention above 100 percent, annual churn below 10 percent and gross margin above 75 percent, in its sell-side due diligence list. Use them as reference points, not rules.

Do not change much yet

Avoid redesigns, price changes and major code rewrites in the first month. You do not yet know why customers stay.

Days 31 to 60: fix the obvious and reduce risk

Fix reliability and support first

Customers forgive a plain product more easily than a broken one. Fix recurring bugs, slow pages and confusing emails before anything flashy.

Reduce key risks

Look at the biggest risks you identified in due diligence and take action.

• One AI model provider. Add monitoring for cost and errors, set usage limits, and test a backup model.
• One traffic channel. Start a second one, such as content, partnerships or email.
• Concentrated customers. Talk to your biggest accounts and improve their experience.
• Missing documentation. Write down how deployments, backups and billing work, so you are not the only one who knows.

Check the outside picture

Run your own domain through the traffic checker to see the modelled traffic, SEO audit and tech stack that others see. Compare against rivals in the AI startups directory, and note differences in pricing and positioning. Everything there is an estimate or a public signal, so use it to find questions, not final answers.

Clean up costs

Review every subscription, API plan and tool. Remove what you do not use. Many small businesses carry forgotten costs.

Fix legal basics

Update the privacy policy, terms and contact details to reflect the new owner. Confirm any required notices to customers, payment providers or app stores. Ask your lawyer which apply.

Days 61 to 90: make your first bets

By now you know the product, the customers and the metrics. Pick two or three improvements, not ten.

Improve conversion or onboarding

Look at the path from signup to first value. Small fixes, such as a clearer first screen or faster setup, often lift activation without new features.

Revisit pricing carefully

If you plan to change pricing, test it on new customers first and keep existing customers on current plans for a while. Check usage costs so you do not lose money on heavy users. See startup valuation multiples for why margin matters for value.

Start a growth experiment

Choose one channel and run it consistently for a month. Options include helpful content, partnerships, listing on directories and outreach to past users.

Plan the next quarter

Write a short plan covering goals, key metrics, budget and the tasks you will outsource. If you used financing, align the plan with your repayment schedule. See financing a startup acquisition.

Mistakes to avoid

• Changing everything at once. If revenue falls, you will not know why.
• Ignoring the seller's workload. Track the hours you spend on tasks the seller used to do.
• Letting support slip. Slow replies lead to cancellations.
• Forgetting the earn-out or note terms. Keep reporting and payment dates in your calendar.
• Skipping rest. Running a business on a side schedule is a marathon.

A simple 90-day scorecard

Check these at day 90.

Area	Question
Control	Do you hold every account, key and credential?
Revenue	Is revenue stable or growing against the baseline?
Customers	Have the top accounts heard from you personally?
Operations	Are processes documented and backed up?
Risk	Have you reduced the biggest dependency?
Growth	Is one experiment running with a clear measure?

If most answers are yes, you have moved from "new owner" to "operator." If you want to benchmark against peers or compare the broader market, use the revenue rankings and read the methodology to understand how estimates are built. And if you are considering a next acquisition, browse the Buy a startup marketplace.

FAQ

What should I do first after buying a startup?

Secure access. Change passwords, rotate keys, enable two-factor authentication and confirm that payments reach your account. Control of the accounts comes before any improvement work.

Should I tell customers about the new owner?

Usually yes, with a short, honest message after closing. Explain that service continues and give them a way to contact you. Avoid announcing big changes until you understand the product.

How much should I change in the first 90 days?

Very little at first. Spend the first month learning, then fix reliability and obvious problems. Make only a few well-measured changes by day 90.

How long should the seller stay involved?

Many deals include 30 to 90 days of support, and some run longer. Longer transitions help if the product is complex, so negotiate the length before you sign.