How law firm marketers use AI to get budgets approved
You know the feeling. Brand awareness gets nods in the marketing meeting, but lands flat in budget conversations. You're speaking one language. Finance speaks another.
The problem isn't that marketing lacks value. It's that we struggle to express that value in terms finance actually uses.
So what framework can you use to bridge the gap?
Start with payback, not ROI
Finance teams care less about ROI percentages than they do about one specific question: how quickly do we get our money back?
Payback period is the metric that matters. Calculate it simply:
Monthly gross profit per customer (your average monthly revenue multiplied by your gross margin) divided into your customer acquisition cost. That gives you months to payback.
If it costs £200 to acquire a customer who generates £50 gross profit monthly, your payback period is four months. After that, they're profitable.
This is the language finance speaks. Use it.
Set a safety limit
Finance teams hate uncertainty. They want to know: what stops this from spiralling?
Give them a clear answer. Set a specific cost-per-acquisition (CPA) or cost-per-lead threshold where you pause and review. Not a vague "we'll keep an eye on it" — an actual number.
A reasonable starting point is 1.5 times your target CPA. If your target is £200, your safety limit is £300. Go above that for two consecutive review periods? Pause and reassess.
This gives finance an off-switch. That single commitment often unlocks budget that would otherwise stay frozen.
Build your evidence properly
When you're forecasting, use your own data first. Your CRM, your analytics, your finance reports.
If you don't have reliable internal numbers, find current benchmarks for your specific sector and region. Not generic figures from 2019 — recent, relevant data you can cite.
If no solid benchmark exists, say so. "I can't find a reliable figure for this" builds more trust than a number you've quietly invented.
Create governance that finance can trust
Wrap everything into a simple structure:
Your safety limit threshold. Your review periods (fortnightly or monthly works for most firms). And clear up/down rules: what happens if results beat expectations, what happens if they don't.
This isn't bureaucracy. It's the framework that lets finance say yes.
Put it all together
Package this into a short summary: context, economics, governance, and your key assumptions. Keep it under 200 words. Make it easy for a cautious CFO to scan and trust.
When you present marketing in these terms, you're not asking finance to take a leap of faith. You're showing them a controlled test with clear parameters and defined exit points.
That's how budgets get approved.
Want help building your case?
I've created an AI prompt that walks you through this entire framework step by step — from calculating your payback period to setting safety limits to producing a finance-ready summary.
Make a copy of the prompt and use it straight away.
Want to hear finance leaders and marketers discuss these principles in depth? The Marketing Meetup webinar on finance buy-in is worth an hour of your time.