NPS for an accounting firm is a single-question score from 0 to 10 ("how likely are you to recommend us") that gives you a measurable read on client loyalty. It's calculated as the percentage of promoters (9 to 10) minus the percentage of detractors (0 to 6). Used well, it predicts referrals and retention faster than any other single metric. Used badly, it becomes a vanity number nobody acts on.
What NPS actually tells you
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?" 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.
Bain & Company, who developed the framework, treat NPS as one of the strongest leading indicators of growth in professional services firms. It moves before churn data does, which means you get a chance to fix problems before they cost you fees.
How to calculate NPS (worked example)
The mechanic is simple. Three steps.
Step 1. Ask clients 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
- Passives — scores 7 and 8
- Detractors — scores 0 to 6
Step 3. Calculate: % Promoters minus % Detractors. Passives don't count.
Worked example. You survey 50 clients and get:
- 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:
- Above 0 — good (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. 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.
When to ask the NPS question
Two cadences work for accounting firms.
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.
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. 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:
The qualitative answer is where you find out what's actually driving loyalty (or dragging it down). Quantitative scores tell you the temperature; qualitative answers tell you why.
For higher-value or detractor responses, also include:
Keep both optional. A short, focused open question gets answered. A long block of "please tell us more" gets ignored.
Closing the loop with 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:
Listen first. Don't argue. Don't justify. Take notes. Where there's something fixable, fix it. Where there isn't, log it.
Most detractors don't expect a partner call. The fact of the call alone shifts perception. Firms that adopt this rhythm typically see detractor counts halve within 12 months.
Turning promoters into reviewers and referrers
Score 9 or 10 with a positive open answer? They're 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?" 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.
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.
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.
Never closing the loop. Surveying repeatedly and never changing anything. 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
- Track trend 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. 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; NPS measures the overall relationship. They give different information — use both rather than picking one.
What's a passive on NPS?
Anyone scoring 7 or 8. They don't count toward the score, but they're at risk of becoming detractors. Worth identifying patterns in passive responses.
Should NPS scores be team KPIs?
Aggregate trend yes, individual scores no. Tying NPS 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/