How to Fact-Check a Sales Deck or Pitch Deck Before It Goes Out

In October 2025, Deloitte agreed to give part of its fee back to the Australian government. A $440,000 report it had written for the Department of Employment and Workplace Relations turned out to contain references that didn't exist, including reports attributed to professors at the University of Sydney and Lund University. The Guardian reported that the corrected version disclosed the use of a generative AI tool chain. The person who first highlighted the errors was Dr Christopher Rudge, an academic at the University of Sydney.

Deloitte stood by the report's findings. That's almost beside the point. Once a reader finds one citation that doesn't hold, they stop trusting the others.

Your sales deck and your pitch deck work the same way. Someone careful will open the sources. If one of them is wrong, every other slide gets read with a raised eyebrow.

This guide is for founders, sales leads and marketing teams who want to send a deck they can defend line by line. It's the method we use, written so your own team can run it before anyone outside sees the deck.

To fact-check a sales deck or pitch deck, list every claim a reader could dispute, decide what kind of evidence each one needs, then open the original source and check it says the same thing for the same market, period and definition. Keep, qualify or cut each claim, and record the result in a claims log before the deck goes out.

Why Decks Get Checked Harder Now

Decks get checked harder because buyers increasingly read them on their own, compare them with what else they can find, and notice when the two don't match. A deck used to be something you talked through. Now it's often forwarded, read alone and checked against your website.

Gartner's surveys of B2B buyers show the pattern. In a survey of 632 buyers run in August and September 2024, 61% said they'd prefer a buying experience with no sales rep at all. And 69% reported inconsistencies between what a supplier's website said and what its sellers told them.

That middle bar is the one that should worry you. If seven in ten buyers have already spotted a mismatch between a supplier's site and its sales story, they're primed to look for the next one. A deck figure that doesn't match your own case study page is exactly that.

The trend hasn't reversed. Gartner's next survey, of 646 buyers in August and September 2025, put the rep-free preference at 67%, and 45% said they'd used AI during a recent purchase.

Investors read fast too. Dropbox, which owns the DocSend deck-sharing tool, says in its pitch deck research that investors spend "less than 3 minutes" on a deck, and that most decks run to roughly 20 pages. In three minutes nobody checks everything. They check the two or three numbers the whole story rests on. Those are the ones that have to be right.

Step 1: Extract Every Claim

A claim is any statement in the deck that a reader could reasonably disagree with or ask you to prove. Start by listing all of them, slide by slide, including the small print on charts and the logos at the bottom.

The usual suspects:

• Numbers: market size, growth rates, customer counts, revenue, savings, conversion and retention.
• Superlatives and rankings: "leading", "first", "fastest", "only", "#1".
• Comparisons: against named competitors, against "the old way", or against an industry benchmark.
• Outcomes and testimonials: what customers achieved, and what they said about it.
• Customer and partner names: logos, case studies, "trusted by" strips and endorsements.
• Regulatory and compliance statements: certifications, approvals, "GDPR compliant", legal positions.

Do this in a spreadsheet. One row per claim. There'll be more than you expect, because chart labels, footnotes and logo strips all count.

My advice is to get someone who didn't write the deck to do the extraction. The author reads what they meant. A fresh reader reads what's on the page.

Step 2: Classify the Source

Every claim needs a type of evidence, and knowing which type tells you where to look. For each row, mark where the support should come from:

• Your own data, such as CRM, billing, product analytics or signed contracts.
• A third-party source, such as a research report, a regulator, a statistics body or an industry association.
• A public record, such as a company filing, a published price list or a court judgment.
• Opinion or ambition, which is fine, as long as it reads as opinion or ambition.

A claim that doesn't fit one of the first three is either an opinion or a risk. "We're the most trusted name in the sector" has no source type at all. It's an opinion dressed as a fact, and a careful reader will treat it as one.

Your own data counts, by the way. "Customers cut onboarding time by 40%" is fine if your product analytics show it, for a defined group, over a defined period. It just needs the definition written down somewhere you can find it in six months.

Step 3: Find, Open and Date the Source

For every claim, write the source next to it with the date it was published or pulled, then open the source itself and check that it says what the slide says. This is the step most teams skip, and it's where nearly every problem hides.

Skipping this step is how a chart ends up meaning something its source never said. Ethan Mollick, a Wharton professor who writes about AI, flagged a widely shared example in September 2025:

Three checks matter most:

1. Is it the original? A blog post or press release quoting a number is a pointer. Follow it to the report, data table or filing it came from. Rounding, re-wording and lost caveats happen at every step of the chain.
2. Does it match? Same market, same region, same year, same definition. A global figure on a UK slide, or a consumer benchmark on a B2B slide, is a very common mismatch.
3. Is it current? Put the year next to any figure that's more than a couple of years old. Readers forgive old data that's labelled. They don't forgive old data passed off as new.

Professional fact-checkers work the same way. Full Fact, the UK fact-checking charity, says in its published FAQs: "Where possible, we refer to data tables, legal documents, or other primary sources". It links every factual statement to its source so readers don't have to take its word for anything. That's a good standard for a deck too.

Full Fact's own short introduction is worth two minutes if you've never seen how a fact-checking team thinks about claims:

Play Video (Loads YouTube)

Step 4: Qualify or Cut

Every claim ends in one of three states: supported as written, supported with a qualifier, or removed. There's no fourth state called "probably fine".

Qualifiers are cheap and honest. Add the period ("in the 12 months to June 2026"), the sample ("across 38 customers"), the scope ("UK mid-market accounts") or the source ("Gartner, 2025"). A qualified claim is usually more persuasive, because it sounds like someone measured it.

Cut anything you can't support and don't need. A shorter deck where every claim stands up beats a longer one with a weak spot. If you want examples of rewrites, I go through them in proof claims on B2B websites.

The UK's advertising rulebook gives you a useful bar to aim for, whether or not your deck counts as advertising. Rule 3.7 of the CAP Code says that before a marketing communication goes out, "marketers must hold documentary evidence" for claims that readers are likely to see as objective. Rules 3.33 and 3.34 add that comparisons with competitors must compare products meeting the same needs, on features that are "material, relevant, verifiable and representative". Those are good tests for a competitor slide.

Pitch decks carry one extra risk. If a deck invites people to invest, it may count as a financial promotion, and the FCA says "All financial promotions must be clear, fair and not misleading regardless of the media type." The rules on who can communicate or approve them are specific. If you're raising, take proper legal advice on that point. This guide isn't it.

Step 5: Sign Off and Keep a Log

A claims log is a one-page table that records every claim, its source and who checked it. It turns a one-off check into something you can repeat when the deck changes, and it's the fastest answer when a buyer or investor asks how you know.

When the deck changes, re-check only the changed rows and update the log. The second check is much quicker than the first, because most rows haven't moved.

If you'd like a scoring sheet to go with the log, the free claims self-audit scores your three to five load-bearing claims against five citation criteria in about 15 minutes.

The "checked by" column matters more than it looks. A name next to a claim changes how carefully people check. It's the same reason we put a named verifier's signature on every Release Assurance report, which I explain in how Release Assurance checks a claim.

Sales Deck vs Pitch Deck: What Changes

The five steps are the same for both. What changes is which claims carry the weight, and who's checking them.

For investor decks, the order of checks follows the order of the story. Mike Vernal, then a partner at Sequoia, talks here about what the best pitch decks have in common. Notice how much of it is about a clear, checkable narrative:

Play Video (Loads YouTube)

If you're preparing for a raise, I've written separately about how investors verify startup claims, including the order they tend to check things in. The free Series A claim checklist turns that into 23 checks you can tick off.

Using AI Without Getting Burned

AI tools are useful for the first two steps and dangerous for the third. They're quick at pulling every claim out of a deck and suggesting what kind of source each one needs. They're unreliable at telling you what a source actually says.

Someone who describes themselves as a former strategy consultant and Big Four junior partner tested Claude and ChatGPT as an associate on a real strategy deck, and posted the results on r/consulting in August 2026. One finding stands out:

The clearest warning came from the High Court in June 2025. In Ayinde v London Borough of Haringey, the court said tools like ChatGPT "are not capable of conducting reliable legal research", and that their answers "may make confident assertions that are simply untrue. They may cite sources that do not exist." The judgment was about lawyers, but swap "legal research" for "market research" and it applies to every deck.

So use AI the way Full Fact describes using its own tools: to support the people doing the checking, not to replace them. A sensible split looks like this.

• Fine to hand to AI: extracting claims, spotting superlatives, suggesting likely source types, drafting qualifiers.
• Never hand to AI: confirming that a source exists, reading the figure off it, or deciding a claim is supported.

I wrote more about why automated deck checks tend to stop short in why most AI deck checks skip the hard part. The short version is that the hard part is opening the source, and that still takes a person.

Where ThriveFinity Fits

Teams checking their own deck are marking their own homework. The claims you've repeated for two years are the ones you've stopped questioning. An outside check is worth having before a funding round, a major tender or a launch, when one weak claim would cost more than the check.

That's what Release Assurance is for. We check every headline claim in a deck, page or proposal against named, dated sources, grade the evidence A to E, rewrite the weak claims, and a named verifier signs the result.

• First Signal (free, under an hour): one claim or one positioning check, so you can see the method before you pay for anything.
• Release Assurance Pack (£699, 3 business days): one asset, every headline claim checked, with a signed Assurance Note.
• Release Assurance Suite (£1,749, 5 business days): three or more assets checked against each other, for example a deck, a one-pager and your website.

You can see what the output looks like in the anonymised Release Assurance sample, and how we grade sources on our methodology page.

We're not the right choice if you need legal sign-off on regulated claims (you need a lawyer), a financial audit of your numbers (you need an accountant), or a deck designed from scratch. And if your deck has five claims and a free afternoon would cover it, use the method above and keep your money.

Pranav Unni

Founder · ThriveFinity Connect on LinkedIn →

Pranav Unni is the founder and lead verifier of ThriveFinity. He reads and signs every paid deliverable personally, and writes about go-to-market decisions for established B2B companies.