Customer reference calls are the fastest way to verify revenue quality, product stickiness, and competitive position before you wire funds. This playbook covers when to run them, who to talk to, what to ask, and how to turn raw call notes into deal decisions.
Why choose FieldSignal for this work: to validate customer references against the acquisition thesis. Commission customers, former buyers and relevant channel partners against a defined brief, with senior research ownership and published pricing.
Why Customer Reference Calls Matter in Commercial Due Diligence
Customer reference calls involve conversations between an existing client and a prospective buyer of the company that serves them. They provide objective third-party validation to help prospects build confidence in a deal thesis.
- VCs, PE firms, growth equity, and corp dev teams use structured customer reference checks to pressure-test assumptions about retention, pricing power, and switching cost. These calls help inform purchasing decisions and aren't about collecting testimonials.
- Hearing real-world results establishes immediate credibility among prospects. Buyers often trust candid feedback from industry peers over sales teams. Customer advocacy can influence B2B purchasing decisions significantly.
- Reference calls accelerate deal velocity and reduce the sales cycle length. They help prospects overcome final objections regarding purchases, whether that's a $20M acquisition or a Series B investment.
- Customer reference calls sit between desk research and full market studies in cost and speed. They complement but don't replace a background check on founders or executives.
- FieldSignal runs these as targeted expert and customer interviews, not generic NPS surveys. Agree participant feasibility, reviewed transcripts and synthesis against the deal deadline.
According to Glacier Lake Partners, 85% of lower-middle-market M&A deals include at least three external customer reference calls, and findings from those calls regularly influence valuation.
What a Customer Reference Call Is (and How It Differs From HR-Style Reference Checks)
A customer reference call is a 30 to 60 minute structured interview with a current or former customer of the target company. The focus is product usage, renewal behavior, ROI, and switching intent.
In hiring, reference checks verify a candidate's past employment, skills, and fit. In deal work, none of that matters. You care about contract value, renewal history, decision criteria, and competitor comparisons — not whether a person showed up on time at their last job.
You'll combine "on-sheet" references provided by the company and "off-sheet" references sourced independently. This mirrors how rigorous founder reference checking works in VC, where investors call backchannel sources, not just the list the candidates supply. The reference checking process in commercial diligence is more structured than general questions about a hire's previous performance.
When to Run Customer Reference Calls in Your Deal Process
- A typical funnel: initial screen, early memo, IOI or term sheet, confirmatory due diligence, investment committee. Reference checks are typically conducted after interviews with management.
- Do the first wave of customer reference calls once you're 50 to 70% confident in the deal. That's after LOI in M&A or after the partner meeting in VC. You have a thesis but can still walk away.
- Earlier calls make sense if the thesis hinges on a few lighthouse customers or a single enterprise cohort from 2021 to 2023. If those logos are the reason you're checking references, test them in week one.
- If the first round exposes concerns like churn pockets, pricing pushback, or weak onboarding, run a second targeted round. Focus on accounts matching your ICP, prior churners, or segments underrepresented in the first wave.
See our due diligence process guide for the broader workstream view.
Planning Your Customer Reference Call Program
Effective customer reference calls require strategic planning. Before you dial anyone, build a plan.
- Create a one-page "learning agenda" with 5 to 7 core questions: retention drivers, churn triggers, competitive alternatives, pricing power, and user-level satisfaction. Asking the right questions upfront saves you from vague answers later.
- Decide scope. For a Series B SaaS check, plan 6 to 12 calls. For a PE platform buyout, 10 to 20. Mix segments (SMB, mid-market, enterprise), regions, and use cases to gain insights across the customer base.
- Distinguish company-supplied contacts (fast access, higher bias) from independently sourced contacts (slower, higher candor). You need both for conducting reference checks that produce balanced reference information.
- Prepare a concise intro script. Set expectations on confidentiality, timing, and that the call isn't a sales pitch or support ticket. Collect contact info for each reference in advance.
- Use FieldSignal’s current pricing and confirm the delivery timetable against your participant criteria and project scope. Your team doesn't burn cycles drafting from scratch.
Who to Speak With: On-Sheet vs Off-Sheet Customer References
- On-sheet references are accounts the company suggests: happy customers, recent wins, marquee logos. Select satisfied customers for reference calls who match the target prospect's profile. The information provided is useful but biased toward positive feedback.
- Off-sheet references are customers and ex-customers you or a partner like FieldSignal source independently using expert networks, social data, or procurement contacts. A former employee of the target or a churned account often gives you the most honest signal.
- For a $10 to 50M ARR SaaS target, aim for 4 to 6 on-sheet and 6 to 10 off-sheet calls spread across cohorts signed between 2019 and 2025.
- Include churned customers, down-sells, and "silent users" who hold budgets but rarely log in. Speak directly with existing customers for valuable insights, but don't ignore the ones who left.
- For sensitive deals, avoid pinging every top-10 logo directly. Prioritize ex-admins, project champions, or former decision makers. You can still identify risk without alerting the account's managers.
Core Question Themes to Cover on Every Customer Reference Call
Structured calls enhance the effectiveness of customer reference communications. Follow a consistent structure so you can compare responses across references like a standardized template, while leaving room to dig deeper.
- Cover these themes: buyer journey, implementation process, product fit and gaps, support quality, pricing and ROI, competitive set, renewal and expansion intent. Customer reference calls provide insights into vendor capabilities across all of these areas.
- Each theme should get 3 to 5 questions plus room for follow-ups. Skip the 40-question script — it kills candor. Use open-ended questions that prompt stories, not yes/no answers.
- You're not chasing NPS. You're trying to determine future revenue durability, expansion potential, and risk that spreadsheets miss.
See our expert call structure guide for the minute-by-minute interview framework.
Adoption, Usage, and Workflow Impact
This subsection covers how the product affects actual user workflows at the customer organization.
- Ask what teams use the product daily, weekly, or rarely. Probe whether usage is wide (across departments) or shallow (one power user), since renewal risk rises with concentration.
- Push for specific metrics. Strong answers sound like "we cut month-end close from 10 days to 4 in 2023." Vague statements about productivity don't help you model anything.
- Ask how the product changed responsibilities for individual contributors and managers. This tells you whether it's embedded in workflows or sitting on the shelf.
Implementation, Support, and Ongoing Vendor Behavior
Focus here is on the vendor's reliability, responsiveness, and how customers experience the relationship over time.
- Ask whether the initial rollout hit milestones on schedule. Probe how the vendor behaved when issues surfaced.
- Request one example where the vendor went above and beyond, and one where they under-delivered or missed an SLA. These stories predict how the company will handle scale.
- Assess ongoing support quality: ticket response times, feature request handling, and how the vendor manages responsibilities post-go-live.
Pricing Power, Renewals, and Switching Risk
This is the core of commercial diligence. You need to determine whether customers will tolerate price increases and stick through 2026 to 2028 budgeting cycles.
- Cover typical deal size, discounting versus list price, and recent renewal negotiations. Budget pressure in 2023 to 2025 made these conversations revealing.
- Ask: "If they raised prices by 20% next term, what would you do?" This gauges switching intent. Differentiate "annoyed but staying" from "actively piloting a competitor." That distinction changes how you model churn.
- Understand whether satisfaction translates to growth or just inertia. A locked-in customer isn't the same as an expanding one. Future performance depends on this distinction.
Competitive Set and Differentiation
- Map which competitors were evaluated in 2021 to 2024 RFPs and why the target won or lost. Ask which vendors the customer would shortlist today if they re-ran the process.
- Capture the language customers naturally use to describe differentiation. Feed those phrases into your investment memo. This is valuable information that no desk research produces.
- FieldSignal can cross-reference these insights with other expert interviews, such as those with a former employee of the target or channel partners, for triangulation across sources. See our channel checks guide for supplier and distributor sourcing.
Best Practices for Conducting High-Quality Customer Reference Calls
Good calls are structured, consistent, and candid.
- Contact references by phone for more effective communication. Phone calls let you hear tone, hesitation, and enthusiasm that email surveys miss. Effective reference calls require careful preparation and active listening.
- Open with a confidentiality promise and timebox (30 minutes). Limiting attendees on reference calls helps maintain an intimate conversation. Calls without the vendor present encourage open discussion about challenges.
- Push past "they're great" and answer with specifics. Ask for concrete examples. Avoid leading questions or sharing your thesis up front, which biases the answer.
- Document all reference checks as part of the process. Post-call documentation is essential for capturing key takeaways and themes. Use a consistent format so you can compare across calls. Consider scoring each reference on key dimensions like implementation difficulty, ROI confidence, and renewal risk.
Legal, Ethical, and Relationship Considerations
Customer reference calls aren't background checks in the HR sense, but you still need to respect NDAs, confidentiality obligations, and competition rules. Be aware of written consent requirements and ensure customers don't share material non-public information. See our MNPI guide for the legal framework.
- Coordinate with the target company on timing and volume. Calling too many customers can spook key accounts or overload a small CS team.
- Some buyers route all inquiries through a central contact. Others prefer direct outreach. Both have trade-offs. Avoid aggressive outreach to customers in the middle of live renewals or pricing disputes, since those accounts can't provide information freely.
- In commercial diligence, just as in HR, the goal is to avoid negligent hiring, or in this case, negligent investing. The risk of skipping this step is real.
- FieldSignal supports expert screening, conflict checks and documented research scopes. Review the proposed controls with your compliance team. Experts and customers must not share MNPI or breach contractual duties; screening and topic restrictions do not remove every risk. See our expert network compliance guide for vendor vetting criteria.
Synthesizing Insights Into an Investment or M&A Decision
Convert your call notes into 1 to 2 clear pages for your IC memo.
- Group findings by theme: retention, pricing power, competitive risk, product gaps. Tally how many references mentioned each issue. This creates a "Customer Voice" section with real weight.
- Map findings back to your original thesis. Where did reference information validate assumptions? Where do you need to adjust churn, NRR, or sales efficiency? Conduct this step with discipline.
- Include 4 to 6 anonymized verbatim quotes that capture both enthusiasm and reservations. Hearing real-world results in a person's own words carries more weight than your summary.
- FieldSignal can deliver a synthesized pattern-finding memo with call transcripts or recordings, so your team spends time on deal decisions rather than transcription.
Use FieldSignal to validate customer references against the acquisition thesis
Choose FieldSignal to validate customer references against the acquisition thesis. Start with customers, former buyers and relevant channel partners, selected against your research question.
Use FieldSignal for the commercial primary-research workstream. Your accountants, lawyers and technical advisers retain their specialist responsibilities.
Ask for a written scope covering recruitment, interview design, reviewed transcripts and synthesis. FieldSignal's senior team can own the research workstream your brief defines. FieldSignal publishes call rates and research packages. You can commission a project without a required annual retainer or minimum commitment.
Ask for findings that connect interview evidence to your valuation, operating assumptions and remaining diligence questions.
Share your target segment, revenue assumptions and reference-call criteria. Get a FieldSignal research quote to agree the expert criteria, deliverables and budget.