Who this is for
Bookkeeper, finance manager or ops lead who has two totals that should match and an unexplained gap, such as a bank against a ledger or a shop against a payment processor.
Month end is close, two totals differ by an amount nobody can explain, and finding it by hand means hours of scrolling through rows.
The result
From two row-level exports for the same period, you receive a ranked list of possible reasons the totals differ. Each reason names the exact rows that, added together, equal the gap within a tolerance you set, and a script checks that sum. A gap no tested reason explains is reported as unexplained, every reason is a proposal for your bookkeeper to confirm, and nothing is posted.
What is included
- Two row-level exports (CSV or spreadsheet) for the same period, one gap per run, up to 20,000 rows each
- A matching key you name, or a proposal for one that you approve
- Reason types tested by code: timing across the period end, duplicate rows, sign flips, missing rows on one side, rounding, exchange-rate differences and transposed digits
- For each reason, the rows involved, their sum, the gap, and what to check next
- A list of rows that match neither side, and a statement when the gap is unexplained
- Up to three gaps per job, one after another
You receive
- The ranked list of possible reasons with row evidence
- The row-evidence sheet for each reason
- The unmatched rows list
- The script and a one-line command to re-run it
- A note of what the proposals cannot show
What is not included
- Posting journals, adjustments or corrections in any system
- Tax, accounting treatment or audit advice: your accountant decides
- Stating a cause as fact
- Access to your accounting or banking systems
- Exports holding names of individuals, unless you remove or mask them
- Reconciling more than three gaps in one job
What we need from you first
- Which two systems or reports, and the size of the gap
- How many rows each export holds
- Whether a matching key exists
- No logins, keys, customer data or payment details in the first enquiry
Never send passwords, keys, customer records or confidential code in the first enquiry. Secure handover is agreed after scoping.
How we check it is done
- On 500 generated gaps every reason shown has rows that sum to the gap within your tolerance, and none is shown otherwise (100%, because this tests code). One shown reason whose rows do not sum fails the whole test.
- At least 10 of the 12 planted breaks have their known cause in the top three proposals, including at least 5 of the 6 your bookkeeper keeps from us until the run. One false row reference, sum outside tolerance or reason asserted as fact fails the whole test; these planted cases are a smoke test, not a population-rate claim.
- All 3 planted gaps with no tested explanation are reported as unexplained, with no invented reason. One invented explanation fails this smoke test; it supports no general rate claim.
- Your bookkeeper reads every proposal and confirms it is labelled proposed, gives a next check and does not assert a cause as fact. One asserted cause or missing next check fails the whole test.
- A second run on the same exports gives identical proposals and sums, and your team re-runs the command you are given and gets the same files.
You re-run the acceptance checks with the steps we hand over, read the results and sign off in writing. Payment follows sign-off.
When we would stop or decline
- You want adjustments posted, or a view on tax or accounting treatment
- The exports are summaries with no row-level data
- The two exports cover different periods and you cannot provide matching ones
- The files hold personal data you will not mask
Questions
Will you tell me the cause?
We tell you the possible causes with the rows that support each. Only your bookkeeper can confirm which is right.
What if nothing explains the gap?
We say so, and list the rows that match neither side.
Do you fix the books?
No. Nothing is posted or adjusted by us.
How is this different from the monthly drift check?
The monthly drift check compares one payment processor's payouts, refunds and fees with ledger entries. This job tests possible reasons for a specific gap between two row-level exports, with the exact rows for your bookkeeper to confirm.
Does a pass mean it will be right next month?
No. A pass describes items like the test sample on the day of the test. It is not a promise about future items, and it does not replace your own checking.
Price and terms
£345 · untested offer price. £345 after the agreed acceptance checks pass and you sign off. No payment before sign-off.
This is a new service with no published client results. The price is a starting point we have not yet tested with buyers. Nothing is ordered or charged by the enquiry. The full specification is on the Synthetic Industry catalogue.