Technology, Media & Healthcare

How to Underwrite a Vertical SaaS Company

Underwrite a vertical SaaS company by separating subscription ARR from embedded payments and transaction revenue, then testing retention within its specific industry. Key metrics are gross revenue retention by customer size, payments attach rate and net take rate, and penetration of the addressable customer count. System-of-record stickiness supports leverage; a small, saturated vertical limits growth.

What makes vertical saas underwriting different

Vertical SaaS serves one industry, such as dental practices, contractors, salons, property managers or credit unions, and often becomes the system of record that runs scheduling, billing and compliance for its customers. Value comes from deep workflow integration, low churn once embedded, and monetization layers beyond subscription, especially embedded payments, payroll, insurance or lending. Risk comes from small business customers who close or consolidate, a finite number of potential customers in the vertical, dependence on payment processor partners, and exposure to industry downturns. Because payments revenue can exceed subscription revenue, understanding its economics is central to underwriting.

Lenders underwrite the subscription base like any recurring revenue credit, but they look closely at payments revenue: whether it is reported gross or net of interchange, who bears chargeback and fraud losses, and whether the processor contract can be terminated. They often give less credit to transaction revenue than to subscription ARR. Equity investors focus on how many more customers in the vertical can be won, how much more revenue each customer can generate through new modules and financial services, and whether the company can expand into adjacent verticals without diluting its product advantage.

Key metrics

Gross revenue retention by customer size

SMB customers in a single industry churn from business closures, ownership changes and consolidation, not just competitive losses.

Payments attach rate

The share of customers processing payments through the platform shows how much of the monetization opportunity has been captured.

Net payments take rate

Payments revenue must be measured net of interchange and processor fees to compare with subscription revenue.

Market penetration

The number of customers won versus total businesses in the vertical shows remaining runway and whether growth will slow.

Revenue per customer

Rising revenue per account from modules and financial services drives expansion when new logo growth is limited.

CAC payback

Vertical focus can lower acquisition costs through referrals and associations, which should show up in faster payback.

Payback under roughly 12 to 18 months is often expected for SMB-focused vertical software.

How to underwrite it, step by step

Split revenue into subscription, payments, other financial services and implementation, and present payments revenue net of pass-through costs.
Build cohorts by customer size and vintage to measure gross and net retention and identify churn caused by business closures.
Review payment processor and sponsor bank agreements for economics, liability for losses and termination rights.
Estimate the total number of addressable businesses and current penetration, using industry association or licensing data where available.
Analyze product module adoption and revenue per customer trends.
Assess competitive position against horizontal software and other vertical players.
Size debt on subscription ARR and contracted payments economics, discounting volatile transaction revenue.
Stress test for an industry downturn that reduces customer counts and payment volumes.

Due diligence checklist

Customer-level ARR and payments revenue by month
Payment processor, payfac and sponsor bank agreements
Payments volume, interchange and net revenue reports
Chargeback, fraud loss and reserve history
Cohort retention by customer size and vintage
Module adoption and pricing history
Industry customer count data and market sizing analysis
Integration partner agreements and APIs relied on
Compliance documentation for industry regulations the software supports
SOC 2 and PCI compliance reports

Key risks and mitigants

Payments revenue overstated by gross reporting

Restate payments revenue net of interchange and processor fees before valuation or debt sizing.

Processor or sponsor bank terminates relationship

Review contract terms and portability of merchant accounts, and assess alternative processor options.

Industry downturn reduces customer base

Stress customer counts and volumes for the vertical's downturn history and size leverage conservatively.

Small, saturated vertical limits growth

Analyze penetration and adjacency plans, and avoid underwriting growth beyond the addressable market.

Chargeback and fraud losses

Review loss history, reserve practices and liability allocation with the processor.

Typical financing and deal structure

Vertical SaaS companies are financed similarly to other SaaS businesses: recurring revenue loans for growth-stage companies, and unitranche or senior term loans sized on EBITDA for profitable ones. Lenders typically count subscription ARR fully and give partial credit to payments revenue depending on contract terms and history. Private equity buyers often finance vertical software acquisitions with significant leverage when retention is high and payments revenue is stable, sometimes adding delayed draw term loans to buy competitors in the same vertical. Founder acquisitions frequently include rollover equity and earnouts tied to ARR or payments volume. Smaller vertical software companies may use SBA 7(a) loans with seller financing.

Red flags

Payments revenue reported gross so that total revenue looks far larger than economic revenue
Gross retention below industry peers with churn concentrated in recent cohorts
Penetration already high in a vertical with few remaining customers to win
The processor agreement allows termination on change of control
Rising chargebacks or fraud losses borne by the company

Frequently asked questions

Why do investors like vertical SaaS?

Vertical software often becomes the operating system for its customers, handling core workflows, billing and compliance. That makes it costly to replace, which supports retention. It also creates opportunities to add payments, payroll and other financial services, increasing revenue per customer. Focused go-to-market through industry channels can make customer acquisition efficient.

How should embedded payments revenue be valued?

Payments revenue should be measured net of interchange and processor costs. Net payments revenue that is stable and tied to sticky customers can be valuable, but it fluctuates with transaction volume and depends on processor agreements. Many investors and lenders value it at a lower multiple than subscription revenue and examine loss liability and contract terms.

What limits the growth of a vertical SaaS company?

The main limit is the number of businesses in the vertical. Once a company wins a large share of customers, growth must come from raising revenue per customer or entering adjacent verticals. Underwriters estimate penetration to judge how long growth can continue and whether projections exceed what the market can support.

Is churn higher for vertical SaaS serving small businesses?

Often yes, because small businesses close, sell or merge more frequently. This churn is not always caused by product dissatisfaction, but it still reduces revenue. Underwriters separate business closure churn from competitive churn and compare retention across customer sizes to understand the underlying stability of the customer base.

Underwrite a vertical saas deal in minutes

Drop a deck or data room. Underridge returns a verdict, investment memo, term sheet and a live model, with every headline figure traced to a page, a formula or a labeled assumption. Ten underwrites free.

Try Underridge free

Educational content, not investment, credit, legal or tax advice. Benchmarks are common practitioner rules of thumb and vary by lender, market and cycle.