A chart of accounts is the list of categories your books are organized into. Every transaction lands in exactly one (or is split across a few), and every report is just those categories summed. Get it roughly right and bookkeeping is calm; get it wrong and you own a junk drawer with subtotals. The good news: “roughly right” is a short list, and the rules for growing it are simple. Here's the lean chart that fits most small businesses, and the three mistakes to design out from day one.
What a chart of accounts actually is
Every account belongs to one of the five types from double-entry bookkeeping: assets (what you have), liabilities (what you owe), equity (your stake), income (what you earn), and expenses (what operating costs). The chart is just your named subdivisions of those five, and your P&L and balance sheet are those names, summed. Which leads to the only design principle that matters: an account should exist if, and only if, you'd want to see its line on a report.
The lean starter chart
| Type | Accounts |
|---|---|
| Assets | Business checking · Business savings · Fixed assets (equipment) · Accumulated depreciation |
| Liabilities | Business credit card · Loan payable (if any) |
| Equity | Owner's contribution · Owner's draw · Retained earnings |
| Income | Sales / service revenue (one to start; split by line of business only when you'd act on the difference) |
| Expenses | Contractors · Software & subscriptions · Rent · Supplies · Meals · Travel · Advertising · Insurance · Professional fees (legal, accounting) · Bank & processing fees · Utilities & phone · Depreciation expense |
Around 20–25 accounts. That's not a beginner training-wheels version; it's genuinely what most service businesses need, and it's close to what tax forms expect (the Schedule C expense lines map almost one-to-one). LedgerMCP seeds a chart like this automatically on every new book; you rename and add from there rather than starting from a blank page.
The three mistakes that ruin charts
1. Too many accounts
“Software: design tools,” “Software: hosting,” “Software: misc” feels organized and reports as noise. Sub-flavors make every categorization a judgment call (which means inconsistency), and inconsistency makes year-over-year comparison meaningless. If you want per-vendor or per-project detail, that's what tags are for: the who and the what-for ride alongside the category, and roll up separately (this is also how 1099 tracking works). Categories stay few; tags carry the detail.
2. The Miscellaneous magnet
Every chart needs an “other,” and every neglected chart becomes 30% “other,” which is 30% of your books saying nothing. Rule: if anything recurring lands in Miscellaneous twice, it earns a real account (or an existing one). A monthly two-minute skim during the close keeps the magnet empty.
3. Personal and business in one pot
The structural fix is two equity accounts, not heroic categorization: personal spending from business funds is Owner's draw; business spending from personal funds is Owner's contribution. Books keep tying to the bank, nothing personal pollutes the P&L, and your CPA stops sighing.
Growing the chart without regret
- Add when a report question repeats. Asked “what are we spending on ads vs. tools?” twice? Split the account. Never split preemptively.
- Rename freely, delete never. Accounts with history get archived, not deleted, because the past still happened. (On LedgerMCP deletion of a posted-against account isn't even possible; archiving is the tool.)
- Let the reviewer see the drift. Categories consistently “corrected” to something else are telling you the chart's names don't match how you think. Rename toward your own vocabulary.
Charts of accounts in the AI era
A lean chart got more valuable, not less, when agents started doing the categorizing. An AI matching transactions against 22 clearly-named accounts is consistent to a degree no tired human is; the same AI facing 90 overlapping sub-accounts inherits your ambiguity and guesses. When you set up books with an agent (Claude · ChatGPT), describe the business in one sentence and let it tune the seeded chart: “I'm a freelance photographer. Add an equipment-rental expense account and a second income account for print sales.” Then let consistency compound: every correction you make teaches the next suggestion.
Starting with a backlog instead of a blank book? Set the chart first, then run the catch-up workflow. Categorization quality downstream is set by chart quality upstream.