How much does an agency tech stack cost in 2026?
A five-person agency should budget roughly £250-500/month all-in for CRM, project management, SEO/AI-visibility, email/automation and AI assistants. Solo consultants can run a lean version for under £100/month.
If you're building a budget or trying to work out whether you're overspending on software, here are real, itemised numbers rather than a vague "it depends" — broken down by team size, so you can compare against your own actual spend line by line.
The five-person budget, itemised line by line
HubSpot Starter (~£75/mo for five seats), Notion (~£60/mo for the team), Semrush Pro (~£117/mo), GetResponse plus a separate automation tool (~£60/mo), and AI assistants per seat (~£85/mo total). Call it £400/month all-in for the full stack.
The solo consultant version, much leaner
HubSpot free, Notion free or personal tier, Kit for email at $9/month, and one AI assistant subscription — a genuinely working stack for under £50-100/month while building toward the full agency version as you grow, covered in our best AI tools for consultants guide.
Where costs quietly creep upward
Extra seats added and forgotten about, annual commitments signed too early before a tool is proven useful, and AI add-ons inside tools you barely use are the three most common sources of tech stack cost creep. Audit subscriptions every quarter, not once a year — a lot can accumulate in nine months unnoticed, especially across multiple tools each adding their own small AI upsell.
The return on this spend, put simply
One recovered lead or one retained client typically covers a month of the entire stack several times over — the spend genuinely isn't the risk here; letting the tools go unused after the first excited month is the real waste to watch for, and it's far more common than outright overspending on any single tool.
A simple quarterly audit routine
Once every three months, list every software subscription, who actually uses it, and whether you could name one specific thing it did for the business that quarter. Anything you can't justify in one sentence is a strong candidate to cancel — this single habit, done consistently, is the most effective cost control most small agencies never implement.
Costs at 10+ people: what actually changes
Past ten people, most tools move to enterprise or business-tier pricing with per-seat costs that don't scale linearly — expect closer to £80-150 per person per month rather than the £50-100 typical at five people, as tools like Semrush and HubSpot add usage-based limits that require higher tiers at that scale.
How to budget for growth without overpaying today
Rather than pre-buying the 10-person tier while you're still a team of five, budget for your current size and revisit pricing tiers explicitly at each hiring milestone. Software costs that scale with headcount should be treated as a variable cost tied to growth, not a fixed cost you lock in ahead of the team that will actually use it.
Cost by team size
| Team size | Rough monthly cost | Core tools |
|---|---|---|
| Solo consultant | £50-100 | Free/entry CRM, Kit, one AI assistant |
| 2-3 people | £150-250 | + Notion, GetResponse |
| 5 people | £250-500 | Full five-layer stack |
| 10+ people | £500-1000+ | Upgraded tiers, extra seats |
Frequently asked questions
How much should a small agency spend on software per month?
Roughly £250-500/month for a five-person team running the full core stack — CRM, project management, SEO/AI visibility, email/automation and AI assistants.
Can a solo consultant run a useful stack for under £100?
Yes — free or entry-tier CRM, Kit for email, and one AI assistant subscription cover the essentials for well under £100/month.
What's the most common cause of tech stack cost creep?
Unused extra seats, annual commitments signed before a tool is proven, and AI add-ons inside tools that barely get used — all worth catching with a quarterly audit.
Is it cheaper to pay annually instead of monthly?
Usually yes per month, but only commit annually once you've run a tool for at least a full quarter and know your team will actually keep using it.
How does software cost change once an agency passes ten people?
Most tools move to enterprise or business-tier pricing with usage-based limits, typically closer to £80-150 per person per month rather than the £50-100 typical at five people.
What's the single most effective habit for controlling software costs?
A genuine quarterly audit — listing every subscription and whether you can name one specific thing it did for the business that quarter. Anything you can't justify is a strong cancellation candidate.
The bottom line: budget by team size, audit quarterly, and let usage — not marketing pages — decide what stays.
The rest of this AI stack series
Part of a full series on AI tooling for agencies and consultants: best AI tools for agencies, what software a marketing agency needs, agency tech stack costs, and best AI tools for consultants.