SaaS Budgeting: How to Forecast and Budget for Software Costs

Software is now the third-largest operating expense for most SMBs. It's time to budget for it like rent.

By The StackMatch Research Team

Software is now the 3rd largest expense for most SMBs

3rdLargest operating expense (after payroll + rent)

25%Average annual software cost growth

55%of SMBs have no software budget

Based on SaaS spend analysis from 900+ SMBs.

Why software needs a budget

Rent gets a line item. Payroll gets a line item. But software — which now rivals both in cost for many SMBs — gets buried in miscellaneous expenses. A proper software budget turns reactive spending into strategic investment. Here's how to build one.

Software costs compound through new subscriptions and automatic price increases.

Step 1: Inventory current spend

List every active subscription, its monthly/annual cost, renewal date, and the department that owns it. Include payment method (credit card, ACH, invoice) and contract term (monthly, annual, multi-year). Most SMBs discover 10-20% more subscriptions than expected during this step.

$5K-$50K

Typical unplanned SaaS spend discovered during inventory

Step 2: Categorize and classify

Group tools by category (Sales & Marketing, Core Operations, Finance, Admin & Security) and by criticality (essential, nice-to-have, experimental). Essential tools are those where switching would disrupt operations. Experimental tools are those with under 90 days of active use.

Step 3: Build the forecast

For each tool, model the current cost, projected increase (most SaaS prices rise 5-15% annually), and usage growth. Add a 10% buffer for new tools and unexpected additions. The result is a monthly software P&L that shows what you'll spend — and when — across the next 12 months.

Software budget breakdown (typical 50-person SMB)

The buffer line is the most important. Without a new-tool budget, every software purchase becomes an emergency approval that bypasses procurement discipline. A $500/month buffer covers the trials and experiments that drive innovation without breaking the budget.

Step 4: Monthly review cadence

Review actual vs. budgeted software spend monthly. Flag departments exceeding budget by 15%+. Track new subscriptions that appeared without approval. Use the review to update next month's forecast. A 30-minute monthly review prevents the 20% cost creep that happens when nobody's watching.

Run the free StackMatch audit to get an automated software budget — we'll inventory your current spend, project annual costs, and flag where you're over budget vs. industry benchmarks.

Run your own audit