Short answer: begin with a free CRM, a simple task manager, your existing document suite, an invoicing tool appropriate to your country, and a password manager. Upgrade only when a repeated bottleneck costs more than the subscription.
The five jobs your stack must cover
A solo consultant does not need an enterprise “operating system.” You need to capture an enquiry, schedule the next step, deliver work, invoice the client and protect access. The best stack is the smallest combination that covers those jobs without copying the same information into three places.
| Job | Free first choice | Upgrade trigger |
|---|---|---|
| Capture clients | HubSpot Free CRM or a structured spreadsheet | You repeatedly lose follow ups or need automated sequences |
| Plan delivery | Todoist Free | Projects require dependencies, approvals or multiple collaborators |
| Documents | Your existing Google or Microsoft account | Client security or retention policy requires a business plan |
| Invoice | Locally appropriate invoice template or local accounting tool | Manual reminders and reconciliation consume billable time |
| Protect access | A reputable password manager | Immediately if passwords are reused or stored in documents |
Our default recommendation
HubSpot Free for the relationship
Use it only for contacts, deal stage, next action and notes. Resist adding marketing automation until there is a real lead flow to automate. The free CRM is useful because the record survives beyond an inbox thread.
Todoist for the work
Todoist fits consultants whose projects are lists with dates, priorities and recurring actions. Move to a more structured product only when work genuinely needs dependencies, resource views or client approvals.
A password manager before an automation tool
Your email, invoicing and client documents all depend on account security. A password manager reduces reused credentials and makes recovery information easier to manage. Compare business availability and regional pricing directly with the vendor before buying.
What we deliberately left out
A separate note app, team chat, advanced automation, proposal software and an AI meeting assistant can all become useful. They are not default requirements. Every additional system creates another inbox, data store, renewal and exit problem.
The first upgrade sequence
- Protect accounts and data.
- Automate invoicing and payment reminders.
- Improve lead tracking.
- Add project structure when client work becomes complex.
- Add marketing tools only after a repeatable offer exists.
Vendor pricing and product limits change. Check the vendors’ current terms and your local tax requirements before subscribing.