An investment banking model is the spreadsheet that turns a company’s financial story into numbers you can lend against or buy. A sanity check is a quick, concrete test that confirms the model does what it says, with results that tie to reality. The list below focuses on the checks that protect credibility and speed diligence.
Context and objective: Build a model you can defend and send
Keep the goal simple: a model that balances, reconciles to filings, reflects credit documents and tax rules, and shows returns and headroom under clear scenarios. If a first-year associate can follow the math and a credit officer can test covenants in one view, you are ready to send. As a rule of thumb, a clean three-statement model with one-page outputs will beat a sprawling workbook every time.
1) Tie out history and keep disclosures coherent
Start by reconciling historical income statement, balance sheet, and cash flow to the latest audited or reviewed financials. Roll retained earnings exactly. If segment definitions changed, update mapping and KPIs so your base reflects the new reporting. Align with ASU 2023-07 segment line items and, if supplier finance exists, add balance sheet and cash flow disclosure per ASU 2022-04. Bridge management’s non-GAAP to GAAP to prevent drifting EBITDA bases across tabs. The payoff is fewer restatement loops and faster diligence.
Must-pass check: Total assets minus total liabilities minus equity equals zero every period.
2) Get three-statement mechanics and error controls right
Run a period-by-period balance check and a cash waterfall that reconciles operating, investing, and financing cash flows to the change in cash. Set a single order for interest, taxes, and noncontrolling interest. Limit circularity to the revolver and interest-on-cash and clearly document the approach. Bring leases through all three statements: ROU assets and lease liabilities roll forward; lease interest in financing; lease depreciation in operating costs. Include a bridge that aligns IFRS 16 or ASC 842 lease impacts with debt-like items used in leverage metrics. Clean mechanics reduce review time and avoid noisy recalculation.
Must-pass check: The balance check and cash waterfall both read zero for all periods.
3) Model the debt schedule with precise rates, timing, and fees
Confirm base rate and day count conventions for each instrument. For USD SOFR, use ACT/360 with the documented compounding or Term SOFR method. Replace any residual LIBOR with SOFR and apply fallback spreads and floors consistent with executed agreements. Match LSTA conventions on margin, periods, business day rules, and payment dates. Model OID, PIK accretion, ticking fees, commitment fees, and prepayment premiums precisely. Include upfront fees in sources and uses, and amortize issuance costs to interest expense. To sharpen rate realism, consider how SOFR floors affect all-in borrowing costs. Accurate cash interest yields correct leverage and fewer late legal edits.
Must-pass check: Accrued interest expense ties to the debt rollforward and the cash interest paid line, considering payment timing.
Tip: Centralize the debt schedule and reference it in ratios, interest, and covenant tabs to prevent divergent rate logic.
4) Protect minimum cash with sound revolver logic
Defend minimum liquidity with clear revolver rules. Sweep cash in two steps: first to target cash via the revolver, then to other tranches if permitted by the waterfall. Calculate period interest on average balance unless the credit agreement specifies daily compounding. For ABLs, cap capacity at the borrowing base net of reserves, apply advance rates and eligibility, include an availability block for letters of credit, and toggle cash dominion for breach cases. This yields realistic liquidity planning and transparent covenant tests.
Must-pass check: Revolver availability never goes negative, and minimum cash is maintained in all cases.
Need a refresher on mechanics? See how cash sweeps and revolvers interact in practice.
5) Model working capital and cash conversion transparently
Build DSO, DIO, and DPO with clear links to revenue and COGS, including seasonality if material. For acquisitions, include inventory step-up amortization and tax effects. If supplier finance programs exist, follow ASU 2022-04 for classification and cash flow presentation, and align EBITDA adjustments with the company’s non-GAAP policy and credit definitions. For factoring or securitization, separate true sales from financing, with discount rate, loss reserve, and servicing cost modeled. Add a toggle to include or exclude structured finance in operating metrics if lenders or agencies view it as debt-like. Transparent drivers produce believable cash conversion and credible free cash flow.
Must-pass check: The cash conversion cycle trend makes sense versus history and peers, with clear operational drivers for any improvement.
For step-by-step build guidance, review working capital schedules and drivers.
6) Separate cash taxes from book taxes and respect limits
Split book tax expense and cash taxes. Track deferred taxes and the valuation allowance. Apply Section 163(j) interest deduction limits at 30 percent of EBIT-based ATI for 2022 onward, with carryforwards for disallowed interest. Respect NOL carryforwards, ownership change limits under IRC 382, and the 80 percent usage cap. Model state rates for cash planning, and include foreign withholding and GILTI at a level that avoids double-counting. In transaction models, tag which fees are immediately deductible versus capitalized and amortized. This yields reliable cash taxes and fewer surprises in coverage or free cash flow.
Must-pass check: The effective tax rate bridges to statutory with labeled adjustments, and cash taxes reconcile to the tax balance sheet.
7) Treat leases and debt-like obligations consistently
Bring leases onto the balance sheet under ASC 842 or IFRS 16, splitting interest and depreciation so EBITDA is consistent with disclosure. If covenants use frozen GAAP or specify lease treatment, present leverage both ways. Tie lease liabilities to the maturity schedule and liability rollforward. Add pensions, OPEB, asset retirement obligations, and environmental liabilities where material, and treat them consistently in enterprise value and leverage. Consistent treatment aligns leverage with credit documents and rating views.
Must-pass check: Net debt equals funded debt plus defined debt-like items minus unrestricted cash, matching the credit agreement’s definition.
8) Get equity bridge and dilution math right
Reconcile basic and diluted shares. Apply the treasury stock method to options and warrants unless convertibles require if-converted treatment. After ASU 2020-06, many convertibles use if-converted with fewer bifurcations, so align diluted EPS with that approach and reflect anti-dilution and dividend adjustments per the indenture. Roll forward SBC, including RSUs and PSUs, with grant, vest, cancel, and settlement logic. Model PSU performance modifiers as scenario inputs. Include buyback and dividend timing and tax effects in cash flows. The result is clean EPS, accurate per-share value, and transparent ownership.
Must-pass check: Diluted shares in EPS and equity value per share agree with the cap table and footnotes.
9) Define performance metrics once and reconcile non-GAAP
Centralize definitions. Define EBITDA, adjusted EBITDA, and free cash flow on a single Definitions sheet and reconcile management’s non-GAAP to GAAP. Label add-backs as recurring or one-time, and cite support. Apply the SEC’s May 2024 guidance on presentation. For credit, build ratios per the draft or executed agreement: net and secured leverage, total interest coverage, fixed charge coverage, and restricted payments capacity. Model pro forma adjustments and run-rate synergies as separate lines with toggles and sources. Clear definitions reduce denominator debates and smooth credit committee review.
Must-pass check: The EBITDA used in leverage tests equals the defined EBITDA after permitted add-backs, with a transparent bridge to GAAP EBIT.
10) Align returns, covenants, and headroom to the same scenarios
Calculate equity returns and credit headroom under the same cases. For LBOs, include fees, ticking costs, working capital at exit, and any roll-over equity in IRR and MOIC. Build exit net debt including financing fees and accrued PIK interest. Reflect baskets, grower baskets, ratio debt, and structural subordination for multilayer structures. Test maintenance and incurrence covenants across base and downside, including springing covenants tied to revolver usage and any equity cure rules. If supplier finance is disclosed, show rating agency leverage views that treat it as debt-like. This aligns return and risk views and speeds committee buy-in.
Must-pass check: Minimum liquidity holds, leverage and coverage pass in base case, and the downside shows the first breach period and size.
Build return tables inside an LBO model and link to a dedicated covenant modeling grid to keep investor and lender views in sync.
11) Use compact scenarios, focused sensitivities, and clear breakpoints
Use named scenarios: Base, Downside, Severe, Upside. Drive them with explicit levers such as volume, price, FX, mix, cost inflation, wages, capex, and working capital. For credit, overlay a SOFR path consistent with forwards and the correct day count and payment timing. Run sensitivities on value drivers like revenue growth, gross margin, SG&A productivity, capex, discount rate, and exit multiple, and show a tornado chart plus a small IRR and leverage table. Keep volatile functions out of the calc chain to speed recalc. For a quick refresher on approach, compare sensitivity vs. scenario analysis.
Must-pass check: One summary page per scenario with EBITDA, FCF, leverage, coverage, liquidity, covenant headroom, IRR and MOIC, and valuation deltas.
12) Deliverable quality: transparency, controls, and an audit trail
Make the file easy to read and audit. Color-code inputs and formulas consistently, and avoid hardcodes in formulas. Remove external links and broken names. Freeze panes, label sheets, set a clean print area, and add a control panel for calc mode, circularity, and scenario selection. Lock inputs after final review, maintain a change log, and version with date and initials. PRA model risk principles such as inventory, ownership, change control, and performance monitoring make a good light framework even for deal models. If you use dynamic arrays or LAMBDA or LET, document them so different Excel builds recalc the same way. A tidy presentation creates faster trust and smoother sharing.
Must-pass check: The model opens without warnings, calculates without intervention, and the executive summary updates when scenarios change.
Common failure modes – catch them fast
- Timing mismatches: Interest and cash taxes accrued mid-period but paid at period end. Standardize period-end conventions and reconcile accrued versus paid.
- Wrong leverage base: Using period-end EBITDA instead of LTM where covenants require LTM. Add explicit LTM toggles and labels on each ratio.
- Mixed measures: Using GAAP EBITDA in one ratio and adjusted EBITDA in another. Feed all ratios from one definitions block.
- Lease inconsistency: Including lease liabilities in net debt but excluding lease interest from coverage. Align both sides to the covenant definition.
- Missed 163(j): Modeling cash taxes without Section 163(j), which overstates the tax shield. Add ATI and carryforward logic.
- Supplier finance gap: Reverse factoring that defers payables and flatters operating cash flow. Add supplier finance disclosure and classify cash flows properly.
- Residual LIBOR: USD LIBOR post-2023. Replace with SOFR conventions and credit spread adjustments per agreements.
- EPS dilution error: Applying treasury stock method to convertibles that require if-converted under ASU 2020-06. Build both and switch based on terms.
A focused pre-send checklist
- History tied out: Latest filings mapped; segments updated for ASU 2023-07.
- Mechanics clean: Balance sheet balances; cash flow reconciles change in cash; circularity limited and documented.
- Rates correct: SOFR conventions set; day count and payment timing match credit docs.
- Revolver logic: Minimum cash respected; borrowing base and cash dominion modeled.
- Working capital: ASU 2022-04 programs reflected; factoring or securitization properly classified.
- Tax engine: Section 163(j) EBIT-based ATI applied for 2022+; NOLs and 382 limits modeled.
- Leases clear: Disclosures reconciled; leverage shows lease treatment both ways if required.
- Equity math: ASU 2020-06 treatment applied; diluted EPS reconciled to cap table.
- Metrics defined: Non-GAAP reconciled to GAAP; SEC presentation guidance respected.
- Return and risk: Base and Downside include headroom; first breach period flagged.
- Sensitivities: Value and covenant breakpoints shown; recalc times reasonable.
- File governance: No external links; consistent colors; protections set; change log present; versions labeled.
Implementation notes that speed up review
- Single definitions tab: Drive all non-GAAP and covenant metrics from one source to cut debates.
- Sources and uses journal: Drive a journal-entry stub so the post-close balance sheet builds automatically.
- Rates store: Hold SOFR curves, spreads, and tax rates with as-of dates in one block for auditable updates.
- Covenant test grid: Show required vs. actual and headroom, both absolute and percentage. Color-code breaches.
- Scenario overrides: List deltas from management’s base so reviewers focus on what changed.
- Rollforward audit lines: Keep beginning, additions, subtractions, non-cash, ending on every roll so reviewers trace movements fast.
- New angle – telemetry: Add a lightweight “recalc time” cell and file hash reference on the cover to track performance and version integrity without macros.
What not to send
- Opaque names: Named ranges or INDIRECT or OFFSET in core schedules that break in other environments.
- Manual calc traps: Files that require global option changes to calculate.
- Unlabeled add-backs: EBITDA bridges with vague lines. If it needs a footnote in the CIM, it needs a label in the model.
- Rate errors: Residual LIBOR, wrong day counts, or omitted fees that drive wrong pricing.
- Single-scenario files: Hiding downside leverage and liquidity when decision-makers expect discipline.
Closeout and retention
Treat the model like a record. Archive with an index, version history, Q&A, user list, and full audit logs. Hash the final file, set retention, request vendor deletion with a destruction certificate when appropriate, and note that legal holds override deletion.
Key Takeaway
These checks protect the two things that matter: trust in the numbers and speed to a decision. Tie out history, get debt and taxes right, defend liquidity, define metrics once, and show returns and headroom on one page. Do that, and your model reads like a well-run business with clear inputs, sensible outputs, and no surprises when the capital shows up.