Preparing for technical due diligence before a funding round or acquisition
A fintech startup prepares for an investor's or acquirer's technical due diligence by mapping its money flows, tracing tests to each flow, proving ledger reconciliation, compiling its incident history, refreshing penetration tests, and mapping regulatory obligations to evidence. The startup ends with dated test evidence in the data room and a remediation plan for every gap found.
When an investor or acquirer asks for technical due diligence
The trigger is a signed term sheet, a letter of intent, or a data room request list with a technology section. The people preparing are the CTO or head of engineering and the founders of a seed to growth stage fintech: a neobank, a Banking-as-a-Service (BaaS) programme, a lending or buy now pay later product, a payment acquirer, or a finance SaaS that moves customer money. Technical due diligence for startups in these segments goes past code quality and architecture. The reviewer asks five questions:
- Test coverage of money flows. Which payment, refund, payout, and fee flows have automated tests, including failure paths such as a refund after a partial capture or a retried webhook?
- Reconciliation. Does the ledger match bank statements, processor settlement files, and scheme reports, and who proves it daily?
- Incident history. Which incidents moved or misstated customer money, what was the root cause, and which regression test now covers each one?
- Security testing. When was the last penetration test, what did it find, and was each exploitable finding retested?
- Regulatory readiness. Which obligations follow from the licence or the partner bank agreement, and what evidence shows they are tested?
What happens when the diligence finds gaps first
The National Venture Capital Association (NVCA) model term sheet makes closing conditional on "satisfactory completion of financial and legal due diligence" and offers an optional representation by founders "regarding technology ownership" (NVCA Model Term Sheet, checked on 2026-09-22). A gap the reviewer documents first becomes a finding in the diligence report, and each finding is negotiated before that condition is met. Typical outcomes are a fix required before closing, a specific representation in the purchase agreement, or a post-closing covenant with a deadline.
These findings recur in fintech technical due diligence:
- Untested money flows. The payment suite covers happy paths only. A retried capture that posts twice, or a partial refund that miscalculates the fee, has no test, so the reviewer cannot tell whether customer balances are correct.
- No reconciliation evidence. Finance reconciles in spreadsheets and engineering has no test against statement files. The regulatory precedent is concrete: the Consumer Financial Protection Bureau (CFPB) alleged that Synapse Financial Technologies failed "to maintain adequate records of the location of consumers' funds" and to ensure those records matched its partner banks' records (CFPB enforcement action, complaint filed 21 August 2025, order entered 12 September 2025, checked on 2026-09-22).
- Stale security testing. An entity subject to the Payment Card Industry Data Security Standard (PCI DSS) performs internal and external penetration tests at least once every 12 months and after any significant change (requirements 11.4.2 and 11.4.3; see PCI DSS testing requirements). A last report older than 12 months, or findings with no retest, is a documented gap.
- Undocumented incidents. An outage or balance error visible in status page history or support tickets, with no root cause record, turns into a question about what else the disclosures omit.
Evidence rebuilt during the review competes with the deal timetable, and the reviewer writes the report from what the data room holds on the day of review.
Technical due diligence checklist: the preparation sequence
- Map money flows. List every flow that moves or records customer money: pay-in, capture, refund, chargeback, payout, fee, interest, and FX conversion, with states and failure paths. Output: a money flow map per product.
- Trace tests to flows. For each state and failure path, record the test, whether it runs in CI, and whether it gates a release. Output: a coverage matrix per money flow with the untested paths marked.
- Prove reconciliation. Run the ledger against bank statements, processor settlement files, and scheme reports for a recent period, and test the double-entry invariants. Output: reconciliation test results and a break history with each break explained.
- Compile the incident register. List incidents that affected customer money or availability, with dates, impact, root cause, and the regression test added. Output: an incident register linked to tests.
- Refresh security testing. Commission web, API, and mobile penetration tests if the last report is older than 12 months or predates a significant change, and retest exploitable findings. Output: a current penetration test report with retest results.
- Map regulatory readiness. For each obligation from the licence, the partner bank agreement, PCI DSS, and privacy law, record the test and its latest result. Identify which systems store, process, or transmit cardholder data. Output: an obligation-to-evidence table per jurisdiction.
- Fix and retest high-severity gaps. Close gaps that touch balances, customer funds, or exploitable vulnerabilities before the data room opens. Output: retest evidence per closed gap.
- Write the summary and the plan. Summarise coverage, controls, and open risks in the reviewer's order, with a dated plan for each open gap. Output: a due diligence summary and a remediation plan for the data room.
Timeline and scope of technical due diligence preparation
Durations are typical engineering estimates for one ledger, one or two payment providers, and one jurisdiction, not company statistics.
| Phase | Duration (estimate) | Roles | Output |
|---|---|---|---|
| Money flow map and coverage matrix | 1 to 2 weeks | QA lead, backend engineer | Money flow map, coverage matrix |
| Reconciliation tests and break history | 1 to 2 weeks, in parallel | QA engineer, finance operations | Reconciliation test results, break history |
| Incident register | 3 to 5 days, in parallel | Engineering lead | Incident register linked to tests |
| Penetration test and retest | 2 to 4 weeks | Security tester, developers for fixes | Penetration test report, retest results |
| Regulatory readiness mapping | 1 to 2 weeks | QA lead, compliance officer | Obligation-to-evidence table |
| Gap fixes, retests, summary | 1 to 3 weeks | Developers, QA engineer, CTO | Retest evidence, due diligence summary, remediation plan |
Scope grows with the number of money flows and payment providers, the jurisdictions with a licence or partner bank, the environments that differ from production, and whether an acquirer also asks for integration risk. Starting before the term sheet shortens the critical path, because the penetration test and its retest are the longest phase.
How we help before technical due diligence
We test money flows, ledgers, and security for fintech startups preparing for a funding round or an acquisition, and deliver evidence in the order a reviewer reads it.
- Steps 1, 2, and 8. QA audit and test strategy delivers the "QA maturity assessment", the "Prioritised roadmap with effort estimates", and the "Due diligence summary for investors or partners". Payment flow testing adds the "Payment flow map with every state, transition, and failure path".
- Step 3. Ledger and reconciliation testing delivers the "Double-entry invariant test suite", "Reconciliation test scenarios against bank, processor, and scheme files", and "Audit trail completeness checks".
- Steps 5 and 7. Security testing delivers the "Web, API, and mobile penetration test report" and "Findings with severity, reproduction steps, and retest results".
- Step 6. Audit and certification test evidence delivers the "Requirement-to-test traceability matrix" and the "Gap report before the assessment".
- Steps 2 and 7. Test automation delivers the "Regression suite for critical money flows" and the "Coverage and run time report".
The investor or acquirer runs the diligence and writes its report. Our evidence and summary are input to that review.
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Scope your technical due diligence preparation
Send your money flows, payment providers, jurisdictions, and the expected data room date, and we return a preparation scope with the evidence each step produces.