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Explain commercial banking income movements from average balances, effective rates and fee products. Build a bridge that separates growth, mix, repricing and funding expense, then reconcile it to the income ledger.
Commercial banking revenue analysis separates income changes into average balances, effective rates, funding expense and fee products. Start with matched income and balance exports, then build a bridge whose components equal the ledger movement. The result tells finance whether growth came from more lending, a different loan mix, repricing or noninterest services.
Use a defined portfolio, legal entity and reporting currency. Keep the same loan products in both periods, while retaining new and exited products as explicit rows. A relationship that moves between teams must not appear as a new relationship for the bank.
Interest income = Average balance × Annualized effective rate × Accrual factor
Defined operating income = Interest income − Interest expense + Included fee income
This is a management analysis boundary. It excludes provisions, operating expenses and other income unless you explicitly add them. It is also different from net interest margin, which needs an average earning asset denominator. The FDIC reports net income and net interest margin separately; label each measure precisely.
Use commercial banking cost analysis for the expense question after explaining income. Do not make an income bridge carry an unshown profitability conclusion.
Bring loan income, average balances, funding interest and fee-ledger exports. Keep period, entity, product, relationship identifier, currency, average balance, recorded interest, effective yield, accrual basis and ledger account. Fee rows also need fee product, posting date, adjustments and an identifier that prevents duplicate postings.
Aggregate daily balances using the same population as the interest ledger. Derive an effective rate from recorded interest when that produces a better tie than a contractual coupon. Distinguish purchase discounts, deferred fee amortization and interest reversals so they can be explained separately when material.
For an Excel summary, suppose the detail sheet has period in A, product in B and recorded interest in C. Put the required period in B1 and product in A2:
=SUMIFS(Detail!$C:$C,Detail!$A:$A,B$1,Detail!$B:$B,$A2)
Microsoft documents SUMIFS as adding values meeting multiple criteria. Sum recorded interest, then derive the group yield from total interest and total average balance; do not average account yields without balance weights. Covirage is not affiliated with Microsoft.
Consider a US commercial bank comparing two illustrative quarters. Both use a 0.25 accrual factor under the example's 30/360 convention. Real exports must retain their actual day-count basis. Rates below are annualized; money is USD.
| Loan product | Prior average balance (USD) | Current average balance (USD) | Prior rate | Current rate | Prior interest (USD) | Current interest (USD) |
|---|---|---|---|---|---|---|
| Commercial and industrial | 100,000,000 | 120,000,000 | 8.0% | 9.0% | 2,000,000 | 2,700,000 |
| Commercial real estate | 50,000,000 | 40,000,000 | 6.0% | 6.5% | 750,000 | 650,000 |
| Total | 150,000,000 | 160,000,000 | 2,750,000 | 3,350,000 |
With prior balance in B, current balance in C, prior rate in D and current rate in E, the two interest columns are:
=B2*D2*0.25
=C2*E2*0.25
Separate total balance growth from product mix using a fixed sequence. First scale prior interest by the change in total average balances. Then price the actual current product balances at prior product rates. Finally move to current rates.
| Bridge step | Calculation | Income effect (USD) |
|---|---|---|
| Total balance growth | 2,750,000 × (160,000,000 / 150,000,000 − 1) | 183,333.33 |
| Product mix | (120,000,000 × 8% + 40,000,000 × 6%) × 0.25 − 2,750,000 × 160 / 150 | 66,666.67 |
| Rate | [120,000,000 × (9% − 8%) + 40,000,000 × (6.5% − 6%)] × 0.25 | 350,000.00 |
| Total movement | 3,350,000 − 2,750,000 | 600,000.00 |
Effects are rounded to cents after calculation. The mix effect is positive because more of the current balance sits in the product with the higher prior yield. The rate effect includes the interaction between changing balances and rates because rate is applied last. Keep that convention unchanged.
Interest growth alone does not explain the defined operating income. Add the funding and fee rows using the same periods and entity boundary.
| Component | Prior income or expense (USD) | Current income or expense (USD) | Effect on income (USD) |
|---|---|---|---|
| Loan interest income | 2,750,000 | 3,350,000 | 600,000 |
| Funding interest expense | 300,000 | 420,000 | −120,000 |
| Treasury service fees | 200,000 | 250,000 | 50,000 |
| Other service fees | 100,000 | 150,000 | 50,000 |
| Defined operating income | 2,750,000 | 3,330,000 | 580,000 |
The proof is $183,333.33 + $66,666.67 + $350,000 − $120,000 + $50,000 + $50,000 = $580,000. That equals $3,330,000 − $2,750,000. Tie each starting component to its ledger account before interpreting the bridge.
Finance owns the reconciliation. Lending leaders investigate balance and yield movements; treasury explains funding expense; product owners explain fee waivers and service activity. A higher effective yield can reflect portfolio changes or accounting adjustments as well as negotiated pricing.
For a different operating business, investment banking revenue analysis follows completed deals and fees. Use retail banking revenue analysis when branch accounts and fee volumes are the relevant units.
Upload your income ledger, average-balance export and fee detail with matched periods. Covirage maps the columns, and its tools compute and check the bridge; the external AI model explains the result with every figure traced to its rows. Create a free Covirage account in about a minute and bring a sample of your own data.
See revenue driver analysis for the supporting balance, rate and mix workflow.
State the scope explicitly. Gross interest income describes earnings on loans and other earning assets. Net interest income subtracts interest expense. An operating revenue view can add selected fee income, but the funding scope and any internal transfer pricing must remain consistent across periods.
Interest accrues while balances are outstanding. A closing balance can include lending completed late in the period that earned little income during that period. Use the ledger's matching average balance and accrual convention, and retain closing balances as a separate exposure measure.
First apply the prior product shares and rates to the change in total balances. Then reallocate current balances to their actual product shares at prior rates. The difference is mix. Finally apply current product rates, retaining the same order each period.