Cost per acquisition (CPA) is the total cost of acquiring one paying customer. It is calculated by dividing your total lead generation spend by the number of leads that converted into completed clients. CPA is arguably the single most important metric in lead generation because it tells you what you actually paid to win each piece of business.
How to Calculate CPA
The formula is straightforward: total spend divided by total acquisitions. If you spend £2,000 on leads in a month and those leads result in 6 completed mortgage cases, your CPA is £333. If your average revenue per case is £800, you have a clear return of £467 per client acquired.
CPA can be calculated across your entire lead budget, or broken down by individual lead source, lead type, or campaign. Breaking it down gives you much more actionable insight. You might discover that your mortgage leads have a CPA of £300, while your insurance leads have a CPA of £80 — both profitable, but with different economics that should inform how you allocate budget.
CPA vs Cost Per Lead
Cost per lead (CPL) and cost per acquisition (CPA) are related but fundamentally different metrics. CPL tells you what you pay for each raw enquiry. CPA tells you what you pay for each completed client. The gap between them is determined by your conversion rate.
This distinction matters because a low CPL does not guarantee a low CPA. If you buy 100 leads at £10 each (CPL = £10) but only convert 1 into a client, your CPA is £1,000. Meanwhile, if you buy 50 leads at £30 each (CPL = £30) and convert 6, your CPA is £250. The higher CPL leads are dramatically more cost-effective when measured by the metric that actually determines profitability.
This is why we always encourage firms to look beyond headline lead prices and focus on CPA. It is the number that connects directly to your bottom line.
What is a Good CPA?
The answer depends entirely on what you earn per client. A CPA of £500 is excellent if your average revenue per case is £2,000. The same CPA is unacceptable if your average revenue is £300.
The key metric to watch is your CPA-to-revenue ratio. As a general benchmark, most financially sustainable lead generation campaigns achieve a CPA that is between 20% and 50% of the revenue per client. So if your average mortgage proc fee is £800, a CPA of £160-£400 represents a healthy and sustainable return.
For different financial products, typical CPA ranges on exclusive verified leads are: residential mortgage leads — £150 to £450; life insurance leads — £50 to £150; equity release leads — £400 to £900; secured loan leads — £120 to £350. These ranges reflect realistic conversion rates and the average number of leads required to generate one completed case.
Reducing Your CPA
There are two ways to reduce CPA: lower your cost per lead, or improve your conversion rate. In most cases, improving conversion rate has a greater impact and is more within your control.
Speed of follow-up is the single biggest lever. Leads contacted within five minutes convert at significantly higher rates than those left for hours. Beyond speed, a structured follow-up cadence — multiple call attempts, SMS messages, and emails over the first 48 hours — ensures you reach leads who did not answer the first time.
Lead scoring also helps reduce CPA by ensuring your highest-quality leads get priority attention. If your capacity is limited, spending your time on the best prospects first maximises your conversion rate and lowers your overall CPA.
Finally, tracking CPA by lead source allows you to shift budget towards the sources that deliver the lowest cost per acquisition, rather than the lowest cost per lead. This single change in mindset — optimising for CPA instead of CPL — is one of the most impactful things a firm can do to improve lead generation profitability.