FINANCIAL STATEMENT INVESTIGATIONS / CASE 01
Booksmrt / Reporting and planning
How to investigate a profit-and-loss statement
A P&L can add correctly and still tell the wrong story. The investigation starts with relationships, then drills into the transactions that moved them.
A useful P&L review has four passes: verify the report scope and method, compare revenue and cost relationships, isolate material movements, and trace those movements to source records and balance-sheet accounts. In the worked six-month dataset, June revenue rises 18% from May while gross margin falls from 51.3% to 43.5%. That combination points to pricing, product mix, inventory cost, cutoff, or classification—not automatically to stronger performance.
Verify what the report actually contains
Confirm entity, date range, accounting method, currency, comparison period, inclusion of closed or eliminated accounts, and whether the report was run after all close entries. A beautiful variance analysis is useless if one month is cash basis and another is accrual basis.
The SEC's financial-statement guide describes the income statement as a report of revenue earned and costs and expenses associated with earning that revenue over a period. That period concept is the first control: test cutoff before interpreting performance.
Source notes: Beginners' Guide to Financial Statements · Publication 538: Accounting Periods and Methods
| Month | Revenue | Cost of sales | Gross margin | Operating expenses | Net operating income |
|---|---|---|---|---|---|
| January | $42,000 | $23,500 | 44.0% | $15,200 | $3,300 |
| February | $46,500 | $23,200 | 50.1% | $15,600 | $7,700 |
| March | $49,000 | $24,600 | 49.8% | $16,100 | $8,300 |
| April | $51,500 | $26,200 | 49.1% | $16,400 | $8,900 |
| May | $55,000 | $26,800 | 51.3% | $20,900 | $7,300 |
| June | $65,000 | $36,700 | 43.5% | $17,400 | $10,900 |
Read relationships before individual accounts
Calculate gross profit, gross margin, operating-expense ratio, and net margin consistently. Plot them beside revenue. A revenue increase with a stable margin is a different story from revenue growth accompanied by collapsing margin.
In this dataset, February margin rises after a January launch discount, then stays near 49%–51% through May. June falls to 43.5%. Because the movement breaks a five-month relationship, it deserves a transaction-level drill-down.
Source notes: Beginners' Guide to Financial Statements
Drill down by amount, vendor, product, and date
Sort June cost-of-sales transactions by size and compare them with prior months. Separate recurring costs from new vendors, manual journals, credits, and transactions posted near cutoff. Reconcile inventory or project subledgers where those systems drive cost.
The worked drill-down finds $4,000 of inbound freight posted to office expense in May and reclassified by a June journal: debit cost of sales, credit office expense. That makes June cost of sales higher and June operating expenses lower, while May retains the original classification. The interactive comparison below puts the classification into May and removes June's journal for analysis; actual posting-period corrections require the close policy and approval.
Source notes: How should I record my business transactions? · Publication 583: Starting a Business and Keeping Records
Watch the margin story change.
The reported June ledger contains Dr Cost of sales / Cr Office expense for $4,000 of May freight. A management comparison puts that cost in May and removes June’s correction. Neither month’s operating income changes.
May
51.3%gross margin- Cost of sales
- $26,800
- Operating expenses
- $20,900
- Operating income
- $7,300
June
43.5%gross margin- Cost of sales
- $36,700
- Operating expenses
- $17,400
- Operating income
- $10,900
Reported presentation: May 51.3%, June 43.5%. Read the journal before interpreting the trend.
Connect the P&L to the balance sheet and cash
Revenue movements should make sense beside receivables, deferred revenue, refunds, and cash collections. Cost movements should make sense beside inventory, payables, prepaids, accruals, and cash payments. This prevents a review from treating timing as economics.
If June revenue grew because $12,000 of annual subscriptions was recorded immediately instead of deferred, the P&L and cash may both look strong while the recognition policy is wrong. If receivables grew faster than sales, the revenue may be valid but liquidity risk has changed.
Source notes: Beginners' Guide to Financial Statements · Publication 538: Accounting Periods and Methods
Write a conclusion that can be challenged
State the observed movement, quantified drivers, evidence reviewed, corrections made, unresolved questions, and the effect on decisions. Avoid labels such as 'good month' when the support only proves a numerical increase.
For the worked file: after normalizing the $4,000 freight classification, May gross margin is 44.0% and June is 49.7%. Neither month's operating income changes. The reported margin decline therefore reverses in the comparable view. This isolates the known classification issue; it does not establish that pricing, inventory, cutoff and every other transaction are correct.
Source notes: Beginners' Guide to Financial Statements