In plain English
Every underwriter, bank, supplier, equipment lender, reads bank statements. Deposits show revenue. Balances show cushion. Payment history shows discipline.
Mixed personal and business accounts cannot be read that way, so the business gets treated as if it has no history at all.
Example
A supplier's credit department asks for three months of business bank statements before setting an opening credit limit.
Why it matters
This one account is the foundation of every credit decision made about you later.
COMMON MISTAKERunning cash sales outside the account. Income you cannot prove cannot be borrowed against.