What is US GAAP?

What GAAP changes

GAAP is accrual accounting with rules: revenue recognized when earned (ASC 606), expenses matched to the periods they serve, leases and equity accounted for consistently. Cash-basis books answer "what hit the bank"; GAAP answers "how is the business actually performing".

When you need it

• Raising from institutional investors — diligence expects GAAP statements
• Bank lending and lines of credit at meaningful size
• Acquisitions, on either side of the table
• SaaS specifically: deferred revenue and 606 treatment are unavoidable

Getting there

A GAAP conversion restates your books on accrual with proper revenue recognition — typically a few weeks of focused work, then a monthly close keeps it current.