NPS for an accounting firm is a single-question score from 0 to 10 (“how likely are you to recommend us”) that measures client loyalty. Net Promoter Score is calculated as the percentage of promoters (9 to 10) minus the percentage of detractors (0 to 6). For UK accounting firms, bookkeepers, limited company directors and small business owners, it’s one of the simplest ways to spot retention risk early, improve service and increase referrals.
This guide explains how to calculate NPS, what a good score looks like for an accounting firm, when to ask the question, how to follow up with detractors and promoters, which common mistakes to avoid, and how to use the results to strengthen client relationships and grow the firm. Used well, NPS predicts referrals and retention faster than most other single metrics. Used badly, it becomes a vanity number nobody acts on.
What NPS actually tells you about customer loyalty
NPS measures loyalty, not satisfaction. The distinction matters.
A satisfaction score asks "did we do a good job?" A loyalty score asks "would you stick your neck out for us?" customer loyalty is a stronger predictor of retention and referrals because it captures not just whether the work was acceptable, but whether the client would actively put their reputation behind you.
Net Promoter Score was introduced in 2003 by fred reichheld and later popularised with Bain & Company, and it is now widely adopted as a leading customer metric. In that same year, the median NPS across 400 companies was just 16. It moves before churn data does, which means you get a chance to fix problems before they cost you fees and supports business growth by increasing retention while promoters also lower marketing costs through word-of-mouth referrals.
How to calculate NPS (worked example)
The mechanic is simple. Three steps.
Step 1. Send an nps survey to existing customers to measure customer loyalty by asking on a scale of 0 to 10: "How likely are you to recommend us to a friend or colleague?"
Step 2. Categorise the responses:
Promoters, scores 9 and 10
Passive customers, scores 7 and 8
Detractors, scores 0 to 6
Step 3. Calculate: % Promoters minus % Detractors. Passives don't count. This is how to calculate net promoter score, and the result is the nps score.
Worked example. You survey 50 clients and get these grouped nps responses, showing how customers are split across promoters, passive customers, and detractors:
30 promoters (60%)
12 passives (24%)
8 detractors (16%)
NPS = 60 - 16 = +44.
The score is expressed as a number, not a percentage. Anything from -100 to +100 is theoretically possible.
What's a good NPS for an accounting firm
Bain's broad benchmarks show how a good nps score depends on different benchmarks across different industries:
Above 0, good score (more promoters than detractors)
Above 20, favourable
Above 50, excellent
80+, world-class
Professional services firms typically sit between 30 and 50. Top-quartile UK accounting firms tend to clear 60. Average NPS levels can vary sharply by sector, though: the average NPS in the insurance industry is 74. If you're below 0, you have an active problem; if you're below 20, you're roughly in line with the wider services average and have room to grow.
The honest caveat: industry benchmarks vary, and small samples (under 50 responses) move the score around significantly. Track the trend over 6 to 12 months rather than chasing a single number, and compare your results with the right average NPS for your sector rather than judging them in isolation.
When to ask the NPS survey question
Two cadences and channels work for accounting firms when you run surveys, and net promoter score surveys can go out in different ways as well as on different schedules.
Post-engagement pulse. Within seven days of a major piece of work, self assessment filed, year-end signed off, advisory project complete. The score reflects the engagement while it's fresh. Practical delivery options include email, SMS, or an onsite pop-up in a client portal.
Annual deep-dive. Once a year, mid-summer. A longer survey with NPS at the start, plus 9 other questions on specific services and communication. Unlike transactional nps surveys sent after a specific interaction, this broader recurring format gives a clearer view of the overall client relationship. See our client satisfaction surveys guide for the full template.
Avoid running NPS during the January self assessment crunch. Response rates collapse and the data becomes unrepresentative.
The follow-up question
NPS without an open follow-up is half the value. Always pair the score with one open question:
After the rating, ask for the primary reason behind the score.
That open ended question is where you turn raw scores into actionable insights, and smart follow up questions make nps feedback far more useful. Quantitative scores tell you the temperature; qualitative answers tell you why.
For higher-value or detractor responses, also include:
What's the one thing we could do that would move your score up by a point?
Keep both optional. A short, focused open question gets answered. A long block of "please tell us more" gets ignored. If you may contact someone personally about their response, it's good practice to ask permission or make sharing contact details optional.
Closing the loop with unhappy customers and detractors
The single rhythm change that moves NPS most:
Score below 7 triggers a personal call from a partner within 48 hours.
Not an email. A call. The script is short:
"Thanks for the honest feedback. I wanted to call directly rather than send an email. Could you walk me through what's prompted the score?"
Listen first. Don't argue. Don't justify. Take notes. Where there's something fixable, fix it; repeated low scores often point to deeper product quality or service issues that need root-cause action. Where there isn't, log it.
Most detractors don't expect a partner call. The fact of the call alone shifts perception. Prompt follow-up with unhappy customers also helps reduce negative word of mouth and customer churn. Firms that adopt this rhythm typically see detractor counts halve within 12 months while protecting customer relationships, not just the score.
Turning promoters into reviewers and referrers
Score 9 or 10 with a positive open answer? They're likely loyal customers and a warm prospect for two follow-up asks.
Review request. A short, personal email asking for a Google review. They've already told you they'd recommend you, the review is the public version of that. See our ask for reviews guide for the script.
Referral introduction. Once you've asked for a review, you can ask: "Is there anyone you've mentioned us to that we should reach out to?" Happy customers can bring in new customers and more customers through referrals, which supports growth and can lower marketing costs through word-of-mouth. The conversion on this is much higher when it follows a positive NPS answer.
Don't bundle both into one ask. Review first, referral two to four weeks later, and use these NPS results to identify valued customers for the next best ask.
Common NPS mistakes
Calculating wrong. The most common error: treating passives as half-promoters or as promoters. They don't count at all in the formula, and focusing on converting passives into promoters is often the quickest way to lift a high NPS into a better result.
Gaming responses. Cherry-picking which clients to survey, or asking "would you give us a 9 or 10?" The data becomes useless.
Ignoring detractors. Receiving a low score and doing nothing. Detractors don't churn quietly, they tell other prospects, and a weak overall NPS can point to wider customer perception problems.
Never closing the loop. Surveying repeatedly and never changing anything. Teams should review NPS data alongside customer feedback, not the score in isolation, or response rates collapse within two cycles.
For the broader reputation context, see our reputation management hub.
Key Takeaways
NPS = % Promoters minus % Detractors (passives don't count)
Above 50 is excellent for professional services; 60+ is top-quartile UK accounting
The open follow-up question carries the real insight
Score below 7 = personal call from a partner within 48 hours
Promoters become your warm review and referral list, supporting customer loyalty and referral-driven business growth
Regularly analyze NPS to track changes in customer perception over 6 to 12 months, not single readings
Frequently Asked Questions
How often should I run NPS?
After every major engagement (post-SA, post year-end), plus an annual deeper survey. An email send works well for the annual survey, with other lightweight channels used for post-engagement pulses. Avoid the January crunch when response rates collapse.
Is NPS reliable for small firms?
At under 50 responses, results swing significantly. Track the trend over 6 to 12 months rather than reacting to single readings.
Can I just use star ratings instead?
Star ratings measure individual transactions, while NPS is a key metric for overall relationship health. They give different information, use both rather than picking one.
What's a passive on NPS?
Anyone scoring 7 or 8. These passive customers don't count toward the score, but they're often the easiest group to convert into promoters. Worth identifying patterns in passive responses.
Should NPS scores be team KPIs?
Aggregate trend yes, individual scores no. NPS can be useful across the whole company when feedback is shared and acted on, but tying it to individual bonuses incentivises gaming. Use it as a firm-level health metric, not a personal target.
Useful Resources
Bain & Company, Measuring your Net Promoter Score https://www.netpromotersystem.com/about/measuring-your-net-promoter-score/
Qualtrics, How to calculate and measure NPS https://www.qualtrics.com/articles/customer-experience/measure-nps/
Retently, 2026 NPS Benchmark https://www.retently.com/blog/good-net-promoter-score/
Net Promoter, Net Promoter Score, NPS, NPS Prism, Net Promoter System, related marks, registered trademarks, and NPS-related emoticons are owned by Bain & Company, Fred Reichheld, NICE Systems, and Satmetrix Systems.