Startup Financial Checklist: First 90 Days

A comprehensive guide to setting up your financial systems when launching a new business.

The first 90 days of a new business are critical. The financial decisions you make early — from your business structure to your accounting system — will have lasting implications. This checklist will help you build a solid financial foundation from day one.

Days 1–30: Legal and Banking Foundation

Choose Your Business Structure

Your business entity affects your taxes, liability, and ability to raise capital. Common options include sole proprietorship, LLC, S-corporation, and C-corporation. Consult with a CPA and attorney before deciding — the right choice depends on your specific situation.

• Sole Proprietorship: Simplest, but no liability protection
• LLC: Flexible, liability protection, pass-through taxation
• S-Corp: Tax advantages for profitable businesses, payroll required
• C-Corp: Best for venture-backed startups, double taxation applies

Obtain Your EIN

Apply for an Employer Identification Number (EIN) from the IRS immediately. This is your business's tax ID and is required to open a business bank account, hire employees, and file taxes. You can apply online at IRS.gov for free.

Open a Business Bank Account

Never mix personal and business finances. Open a dedicated business checking account and, if needed, a savings account for tax reserves. This separation is essential for accurate bookkeeping and protecting your liability shield.

Days 31–60: Accounting and Tax Setup

Choose an Accounting Method

Cash basis accounting records income when received and expenses when paid — simpler and common for small businesses. Accrual accounting records income when earned and expenses when incurred — required for businesses with inventory or revenue over $25M.

Set Up Accounting Software

QuickBooks Online is the industry standard for small businesses. Set up your chart of accounts, connect your bank accounts, and establish a consistent bookkeeping routine from the start. Other options include Xero and FreshBooks.

• Set up your chart of accounts
• Connect bank and credit card accounts
• Create invoice templates
• Set up expense categories
• Establish a weekly bookkeeping routine

Register for State Taxes

Depending on your state and business type, you may need to register for sales tax, payroll tax, and state income tax. Requirements vary significantly by state — consult with a local CPA to ensure compliance.

Days 61–90: Financial Controls and Planning

Create a Budget

Build a 12-month operating budget that includes projected revenue, cost of goods sold, and operating expenses. This becomes your financial roadmap and the benchmark against which you measure actual performance.

Set Up Payroll

If you have employees or are paying yourself a salary (required for S-corp owners), set up payroll through a service like Gusto, ADP, or Paychex. Payroll compliance is complex — using a dedicated service reduces the risk of costly errors.

Establish Financial Review Habits

Schedule a monthly financial review to examine your income statement, balance sheet, and cash flow statement. Understanding your numbers is not optional — it's the foundation of every good business decision.