The $0 Small-Business Software Stack: Free Tools for Every Job (2026)
Free-plan limits verified on Oct 2026 · Updated October 16, 2026
You can run the back office of a small business on free plans. Every free plan has a ceiling, though, and the trick is knowing which ceiling you’ll hit first. This stack picks one free tool per job and lists the limit that matters most.
The stack at a glance
| Job | Tool (free plan) | Key free limits | Source |
|---|---|---|---|
| Invoicing | Zoho Invoice | 500 invoices/year, 2 users, 3 projects | pricing |
| CRM | HubSpot Free CRM | Up to 2 users and 1,000 contacts, no expiration | product page |
| Scheduling | Cal.com Free | 1 user, unlimited event types & calendars | pricing |
| Email marketing | MailerLite Free | 250 subscribers, 2,500 emails/month, 2 seats | pricing |
| Forms | Tally Free | Unlimited forms & submissions (fair use), 10 MB per file upload | pricing |
| Tasks / projects | Trello Free | Up to 10 boards and 10 collaborators per Workspace, 10 MB/file | pricing |
| Business email | Zoho Mail Free | Up to 5 users, 5 GB/user, one domain, no IMAP/POP | pricing |
All limits checked on the vendors’ pages in October 2026.
1. Invoicing: Zoho Invoice
Zoho Invoice includes recurring invoices, automated payment reminders, quotes, expenses and a client portal at $0. Its FAQ caps the free plan at 500 invoices a year, two users and three projects. Invoices show “Powered by Zoho Invoice,” and inactive accounts (180+ days) face data deletion after a warning. If you need more clients and invoices than that, compare it with Wave and Invoice Ninja in our free invoicing apps comparison.
2. CRM: HubSpot Free CRM
HubSpot says its free CRM is free “with no expiration date” and supports up to two users and 1,000 contacts. The free tier includes contact management, deal pipelines, CRM import, the Breeze AI assistant and a reporting dashboard. HubSpot’s page also lists free forms, landing pages, email marketing, a meeting scheduler and live chat. Paid Starter starts at $15/month per seat and removes HubSpot branding.
Ceiling to watch: 1,000 contacts. Clean your list before importing everyone you’ve ever emailed.
3. Scheduling: Cal.com Free
For one person, Cal.com’s free plan has no cap on event types, calendar connections or meetings. It also takes Stripe and PayPal payments. Team features like round-robin start at $12/user/month billed yearly. See our scheduling comparison for Calendly and TidyCal.
4. Email marketing: MailerLite Free
MailerLite Free covers 250 subscribers, 2,500 emails a month, two user seats, one website, one landing page and three active forms. It also allows 3 active automations of up to 5 steps each. MailerLite’s FAQ says that if a free account goes over 250 active subscribers, “sendings will be locked” until you upgrade or remove subscribers. Paid Comfort starts at $12/month.
Ceiling to watch: 250 subscribers comes quickly. Plan your upgrade before you run a big signup push.
5. Forms: Tally Free
Tally offers “unlimited forms and submissions, completely free” within its fair-use guidelines. That includes payments, signatures, file uploads, conditional logic, webhooks, and Google Sheets, Notion, Airtable, Zapier and Make integrations. File uploads are capped at 10 MB per file unless you upgrade to Pro (€20/month), which also removes Tally branding.
6. Tasks and projects: Trello Free
Trello Free is “free for up to 10 collaborators per Workspace,” with up to 10 boards per Workspace, unlimited cards, unlimited Power-Ups, unlimited storage at 10 MB per file, and 250 Workspace command (automation) runs per month. Standard is $5/user/month billed annually.
7. Business email: Zoho Mail Free
Zoho Mail’s free plan gives custom-domain email for one domain, 5 GB of mail storage per user, and up to five users. Zoho’s FAQ says “The Free plan includes up to 5 users at no cost.” Access is through the web and Zoho’s mobile app. IMAP, POP and ActiveSync are not included, so you can’t use Outlook or Apple Mail with it on the free plan.
Note: custom-domain email assumes you already own a domain, which usually isn’t free. Without one, a regular free personal email account is the realistic option.
Where the $0 stack breaks first
- Email list hits 250 subscribers (MailerLite).
- CRM hits 1,000 contacts (HubSpot).
- You hire your 3rd person (Zoho Invoice and HubSpot both allow two users on free).
- You want Outlook or Apple Mail for business email (Zoho Mail Free has no IMAP/POP).
Upgrade the tool that blocks revenue first, usually email marketing, and keep the rest free.
Plan details change. Always confirm on each vendor’s pricing page. We compared published plan details rather than running hands-on tests.