Cash vs Accrual Accounting: When Your Startup Has to Switch

Cash basis accounting is a method that records revenue when you receive payment and expenses when you pay them. Accrual basis accounting is a method that records revenue when you earn it and expenses when you incur them, regardless of when cash moves.¹ A startup has to switch when customers prepay, vendors bill on terms or investors want GAAP.

I work with founders in the four industries I go real deep in: technology (AI and SaaS), healthcare and biotech, pharma, and pharmacy, and in all four I see the same moment. A founder has run on cash basis since day one because the bank balance is easy to read, and then somebody across the table asks for accrual books. I am not a CPA, so your auditor and tax partner own the attest and tax questions.

This is the conversation I would have with you over coffee if you asked what these two words mean and whether you need to care yet. No jargon first, and every number below is on one made-up quarter so you can follow the math with a pencil.

Start with the call you do not want. Your cash books say the company made $56,000 last quarter, and you are proud of that number. An associate at the fund asks for the balance sheet, and there is no deferred revenue, no accounts payable and no accrued payroll on it. She sets your cash profit aside and rebuilds the quarter on accrual. On the illustrative numbers below (not a client) it comes out to a $119,000 loss.

Wait, what is the difference between cash and accrual?

Those two definitions are the whole idea. Here is the coffee shop version. You pay $24,000 for a year of insurance on August 1. Cash basis says you spent $24,000 in August. Accrual says you used 2 months of it by September 30, so $4,000 belongs to this quarter and the rest is paid for and not used yet.

That idea shows up in a few places, so it is not just my opinion. The IRS says accrual-method taxpayers generally report income in the year they earn it.² FASB's concepts statement says accrual accounting reflects what a transaction does to the company in the periods it happens, "even if the resulting cash receipts and payments occur in a different period."³ And under the revenue standard (ASC 606), Deloitte's roadmap explains, revenue is recognized when you satisfy a promise to the customer, which turns on when control transfers.⁴ If you want one line to repeat to your board: revenue follows delivery, not the deposit.

You may also hear that GAAP requires accrual. Two software vendors, Brex and Ramp, both say so in their own guides, and Brex adds that GAAP is a set of guidelines, not a law.⁵⁶ Two other words come up on nearly every call. Deferred revenue is the cash you are holding for service you have not delivered yet, and the formal name is a contract liability.⁷ I cover it in what deferred revenue is in SaaS. An accrued expense is a cost you have incurred and not paid, like wages earned in September and paid in October.⁸ Cash books have no place to put either one. That missing place is the why behind the number.

So are we profitable or not?

Both answers can be true. Here is the back of the napkin version, on illustrative numbers (not a client). A software startup sells monthly subscriptions and a few annual contracts. Its July to September quarter on cash basis looks like this:

1. Cash in: $120,000 of monthly subscriptions collected, plus 4 annual contracts at $45,000 each, prepaid on September 1, for $180,000. Total $300,000.
2. Cash out: $150,000 of payroll, $40,000 of hosting and software, $30,000 of contractors and a $24,000 annual insurance policy paid on August 1. Total $244,000.
3. Cash basis result: $56,000 of profit.

Now rebuild the same quarter on accrual. Nothing about the bank changed. We only move each item to the month it belongs to:

1. Revenue: $120,000 of monthly subscriptions, plus $15,000 for the first month of the annual contracts ($180,000 divided by 12), plus $10,000 of usage billed on September 28 and not yet paid. Total $145,000, and the other $165,000 sits in deferred revenue.
2. Payroll: $150,000 paid, plus $22,000 of wages and bonuses earned in September and paid in October. Total $172,000.
3. Hosting and software: $40,000 paid, less $8,000 for June usage paid in July, plus $14,000 for September usage billed in October. Total $46,000.
4. Contractors: $30,000 paid, plus $12,000 of work done in September and not yet billed. Total $42,000.
5. Insurance: a $24,000 policy with 2 of 12 months used. Total $4,000, and the other $20,000 sits in prepaid expenses.
6. Accrual basis result: $145,000 of revenue less $264,000 of expenses is a $119,000 loss.

Now tie it out, the way I would for a board. Cash profit of $56,000 against an accrual loss of $119,000 leaves a $175,000 gap. That gap is $165,000 of customer money you collected and have not earned, less $10,000 you earned and have not collected, plus $20,000 of net expenses that accrual books recognize and cash books do not ($22,000 of wages, $6,000 of net hosting and $12,000 of contractors, less $20,000 of insurance that belongs to future months). Neither view lies about the bank. Cash tells you your runway today, and accrual tells you whether the model works. You need both, and an investor reads the second.

Does this ever go wrong in the real world? Yes, and the SEC has charged it in a public software company. In June 2022 the SEC alleged that Synchronoss improperly recognized revenue on some license and hosting transactions "upfront, instead of ratably over the term of the multi-year arrangement," in a restatement that covered approximately $190 million of revenues.⁹ A separate SEC order says that under GAAP the revenue for the audit services in a deal could not be recognized upfront in its entirety.¹⁰ Those are allegations, and Synchronoss is not a startup. But a cash ledger treats every annual prepayment that way by design, which is why I do not trust cash books once prepayments start.

Why does my investor care which one I use?

Because they cannot compare, price or trust a company whose revenue moves with the deposit date. Promise Legal's Series A guide lists what diligence needs, and one line reads "Clean books using accrual accounting (not cash basis)."¹¹ Carta says audit readiness reaches any transaction, whether a raise, an acquisition or a secondary, and that many investors require later-stage startups to provide audited financials.¹²¹³ Since GAAP requires accrual, expect cash books to need converting before anyone will audit them. QuickBooks' own guide says businesses are generally expected to use accrual for general purpose financial statements.¹⁴

Lenders want the same discipline. Foley Hoag's venture debt primer says loan agreements carry periodic reporting obligations, including annual audited financial statements.¹⁵ Promise Legal puts investor review at 4 to 8 weeks and first pitch to closing at 3 to 6 months on average, and advises preparing 6 to 12 months before you raise (its own estimates, not data).¹¹ My take is simple: convert at least two quarters before your first investor conversation. If diligence starts while your books are on cash, you are converting under a deadline with a buyer watching.

The older cautionary tale is a cost that never gets accrued. The SEC's 2002 complaint against former Waste Management executives alleged that the company under-accrued its liabilities from self-insured losses, and the SEC's release describes an alleged scheme from 1992 into 1997 that overstated profits by $1.7 billion.¹⁶¹⁷ Waste Management is far bigger than your company, but a cash ledger hides the same thing: a cost you owe shows up as profit until somebody pays it.

How do I know it is time to switch?

Very small companies often start mostly on cash basis, and that is fine, because early on the bank balance is the truth. Here are the 4 signs I look for:

1. Customers prepay. An annual or multi-month prepayment means cash arrives before the work does. In the example above, $180,000 looked like revenue the day it landed.
2. You owe people you have not paid. Payroll that straddles month end, vendor bills on 30 day terms and contractor work not yet invoiced are accrued expenses, and cash basis cannot see them.
3. Revenue follows usage, milestones or reimbursements. You earn it before the payment shows up, and the gap between the two is your accounts receivable.
4. Someone outside the company asks. An investor's diligence list, a lender's reporting covenant, an auditor or an acquirer.

I move a company to accrual when the first of these 4 shows up, and in my book the first annual prepay is the line. After that, every month on cash basis makes the lookback longer and the cleanup more expensive.

What actually changes in my books when I switch?

Five things change. First, you build an opening balance sheet on the switch date that carries receivables, prepaid expenses, accrued liabilities and deferred revenue, because cash books hold none of them. AccountingTools' conversion steps start by recording receivables and sales for all billings issued and not yet collected, which the page says can be a substantial amount.¹⁸ Second, your monthly close gets longer, because someone has to accrue what you owe and defer what customers paid early. I walk through that rhythm in how the month-end close works.

Third, I tie every new account to something outside the books, like an aging report, a contract schedule or a roll forward schedule. Fourth, your reports change shape: revenue gets smoother, and you need a cash flow view to see the bank. Fifth, someone has to own the estimates, and I explain who in bookkeeper vs controller vs CFO.

A word on the report toggle, because founders ask me about it all the time. QuickBooks Online can run a report on accrual basis, and that report counts income and expenses regardless of whether the invoice or bill was paid.¹⁹ That helps, but a toggle only rearranges what is in the ledger. If nobody entered the invoice, the accrued payroll or the deferred revenue, the accrual report has nothing to count. In my book a toggle is a preview, not a conversion.

Tax is a separate question and not mine to answer. For tax years beginning in 2026 the IRS sets its section 448(c) gross receipts test at $32,000,000 or less in average annual receipts, and a change in tax method is requested on Form 3115.²⁰²¹ Island Waters is not a CPA firm, so ask your tax partner before you change anything on the tax side.

How long does the switch take?

It depends on how many months you have to restate and how good the support is, so I will not promise a number. The best outside timeline I found is Promise Legal's advice to start preparing 6 to 12 months before a raise.¹¹ The rest comes from my own history. When I joined a specialty pharmacy, a private equity group had laughed it out of the room because its books were a mess. My first job was to go three years backwards and close the books under GAAP so an audit could be done, and it took about 9 months. Closing those years under GAAP put every one of those periods on accrual.

That is why I tell founders to convert while the lookback is one year, not three. A company that waits until the term sheet arrives has a long project, and it pays for the cleanup twice.

If you run a biotech, pharma, pharmacy or AI company, what changes?

In biotech and pharma, the big accrual is clinical trial cost. Monopar Therapeutics' June 2026 10-Q says it accrues those costs based on the percentage of work completed over the life of each study.²² Deloitte's life sciences guide says services performed by others in R&D should be expensed as the entity becomes contractually obligated for them, which is not the same day the invoice is paid.²³ Through a High Rock Accounting engagement, I was the sole accountant on a clinical-stage biopharmaceutical client's month-end close, owning its preclinical, clinical, manufacturing and general accruals through its Nasdaq IPO. On cash basis, a trial that is running and has not been invoiced costs nothing, and that is the whole problem.

In pharmacy, the money arrives late and sometimes gets pulled back. CMS describes direct and indirect remuneration as fees, payments or payment adjustments made after the point of sale that change the cost of Part D covered drugs.²⁴ An NCPA vice president told Pharmacy Times in 2017 that "These fees are being withheld from us in a lump sum months down the road."²⁵ Rite Aid's fiscal 2019 10-K says third party payors made up substantially all of its pharmacy sales, with its top five at 80.4%, 78.6% and 77.1% of pharmacy revenue over three years.²⁶ When payors hold that much of your revenue, receivables and adjustments are not a footnote.

For AI and SaaS, billing and earning drift apart fast. Snowflake's 10-K says that, unlike a subscription business, it states "we generally recognize revenue on consumption."²⁷ PwC's software guide shows a $90,000 contract over 36 months earning $2,500 a month.²⁸ Deloitte describes a practical expedient for revenue you have a right to invoice, with conditions, so ask your auditor first.²⁹

If you only do 4 things after reading this, do these:

1. Bridge one quarter. Rebuild your last quarter on accrual in a spreadsheet and write down the gap.
2. Count the signs. Tick which of the 4 signs are true today. One is enough to start.
3. Pick a switch date. The first day of a month, with an opening balance sheet that ties to the bank.
4. Call your tax partner. Ask what changes on the tax side before you touch anything there.