Glossary
Book-to-Tax Reconciliation
A book-to-tax reconciliation explains why the net income in a company’s financial statements differs from the net income on its tax return. In a transaction it is a verification step, not a tax exercise. The return was filed with a tax authority by an external preparer, usually long before anyone contemplated a sale, which makes it one of the few numbers in a private business that was produced for somebody other than the owner. We tie the financial statements to it on every quality of earnings engagement, alongside the proof of cash and the payroll summary, and internally we call it the tax bridge to FS.
Where it sits in the work
The reconciliation belongs to the integrity block of the data book: the handful of tabs that establish whether the financial statements can be trusted at all before anyone starts arguing about add-backs. Proof of cash, payroll summary, book-to-tax rec. Those three answer a single question between them, which is whether the reported numbers are the real numbers.
The method is a bridge rather than a comparison. We start from the figure in the financial statements and rebuild it to the tax return, line by line, aiming to land on exactly the same number. Where it lands, the exercise is done. Where it does not, the gap is the work.
How far we can take that rebuild depends on the size of the business. On a one or two person shop we can usually reconstruct the return more or less completely and get back to the financial statements without much difficulty. As businesses get larger the exercise gets harder and the reconciliation becomes more of a tie-out than a full reconstruction.
Reading the result
This is the part that trips people up, because the test works backwards from how most tests work.
A clean reconciliation is uneventful, and that is exactly the signal. Where net income on the financials sits close to net income on the return, there is very little to discuss and we say so in the report. Seeing a business’s financials this close to its taxes is a good sign in itself. It means nobody has been doing anything aggressive in the translation from statements to filings, telling one story internally and a different one to the tax authority.
Small differences do not disturb that. On one engagement the general ledger tied to the profit and loss and the profit and loss tied to the return within about a thousand dollars, and the residual traced to an other-income line we had not picked up. That is a match.
Where it does not close, there is a reason to investigate. The gap is not an accusation by itself. But an unexplained gap is the thread you pull, and it usually leads somewhere real.
What normally explains a difference
Basis, by a wide margin
Where the return is prepared on a cash basis and the financials on an accrual basis, revenue can look wildly apart and still be entirely correct. On one file the revenue difference was enormous until we took the increase in receivables over the period into account, after which the two income figures were close to identical. The remainder traced to movement in accounts payable, bad debt, and inventory. Cash vs accrual accounting covers why the two views separate so far.
Inventory and cost of goods sold
The same file showed materially higher cost of goods sold on the financials than on the return, because the business was expensing purchases straight through the profit and loss while booking opening balance sheet adjustments that never touched it. On another, the return reported higher cost of goods sold on the basis that inventory had increased substantially during the year. Whether that was a real inventory build or a tax-side opening balance entry was not a rhetorical question: if it was real, adjusted EBITDA was higher than management had presented. We went back to the company to find out rather than assume either way.
Year-end adjusting entries
the external accountant books once annually and that never reach the interim months.
Provisions and allowances
recognised in the books and treated differently on the return.
The discrepancy that was also an add-back
The most useful thing a reconciliation does is catch a number that has quietly become an adjustment.
On one engagement a reconciling item from the seller’s accounting system had made its way onto the add-back schedule, presented as a legitimate normalisation. We did not think it was. Reconstructing it meant pulling the old desktop accounting file, the current online file and the bank statements together to find where the amount had actually landed. The offsetting entry turned out to sit in the payroll bank account rather than the operating account, which is not what a genuine reconciling item looks like, and the add-back did not survive.
That is the case for doing the reconciliation properly rather than accepting the schedule you are handed. See quality of earnings due diligence for how the adjusted EBITDA figure gets built around findings like that one.
Comparing against the company’s own accountant
The seller’s CPA has usually prepared a reconciliation already, and it is genuinely useful. We build ours independently and then compare starting points.
On one file we walked through the accountant’s reconciliation with him directly. His book income after his own payroll reconciliations landed close to where ours did once we accounted for a large reconciling item he had treated differently. Two independent reconciliations converging is far stronger evidence than one, and the conversation that produces the convergence is often where you learn what actually happened in the accounts.
Where a difference does not resolve, our practice is to get the explanation in writing before proceeding.
Accounting system changes break it
Where a company has migrated accounting systems mid-period, expect the reconciliation to be the hardest tab in the book.
We have worked files where the business ran two systems in parallel for months, where the extracts supplied from the legacy system arrived on a cash basis while the new system’s data was accrual, so nothing tied until the basis was aligned. The numbers were not wrong. They were not comparable, which is a different problem and a slower one. It is also why a general ledger with thin transaction descriptions after a migration, deposits posted with no customer attached, adds days to diligence that nobody budgeted for.
What it does and does not do
| Ties the financials to an externally filed document | Yes |
| Detects a business reporting two different stories | Yes |
| Explains basis, timing and inventory differences | Yes |
| Catches reconciling items masquerading as add-backs | Yes |
| Confirms the tax return itself is correct | No |
| Constitutes tax due diligence | No |
| Replaces an audit | No |
Treewalk performs financial due diligence. We do not perform tax due diligence, and we do not provide audit or attest services. Where a deal needs genuine tax diligence, state and cross-border exposure, filing position risk, we work alongside a tax specialist and refer that scope out. What we do is tie the return to the financial statements, assess whether the numbers make sense together, and flag what does not.
Frequently asked questions
Is a difference between my books and my tax return a problem?
Usually not. Basis, timing of accruals and inventory treatment routinely produce differences and they are expected. What matters is whether the difference reconciles. An explained gap is fine. An unexplained one gets a question and, if it does not resolve, an explanation in writing.
Why does a buyer look at my tax return at all?
Because it is one of the very few financial documents in a private business prepared for an external party before a sale was contemplated. That independence is what gives it value as a check. Where the financials tie to the return and a CPA also prepares compilation statements, the risk of misrepresented revenue or omitted expenses drops considerably.
My statements and return are almost identical. Is that good?
Yes, and buyers read it that way. It is one of the quieter positive signals in a diligence file.
Can you use the reconciliation my accountant already prepared?
We read it and it helps. We also build our own and compare, because a difference in starting point is exactly the kind of thing that gets carried forward unexamined. Where the two converge, that is a much stronger result than either alone.
Is this tax due diligence?
No. It is a financial diligence procedure that uses the return as a reference point. We do not assess filing positions, tax compliance or cross-border exposure, and we bring in a tax specialist where a deal needs that.
We just changed accounting systems. Does that matter?
It matters a lot. Migrations produce parallel-running periods, extracts on mismatched bases and thin ledger descriptions, and the reconciliation is where all of that surfaces. Getting the old system’s data exported cleanly, on the same basis, before the process starts will save real time.
Where to next
If your financial statements and your tax filings have never been reconciled to each other, it is worth resolving before a buyer does it for you, while the working papers are still to hand and the people who made the entries still work there. Our transaction advisory services team runs this on every engagement. Read proof of cash for the companion test on the cash side, and buy-side due diligence for how the pieces fit together. To talk through a specific deal, email Avnit Sekhon at avnit.sekhon@treewalk.com.
