--- title: "K40 Pro Fingerprint Not Recognised: Causes and Fixes | Qyvea" url: https://qyvea.co.ke/zkteco-k40-pro-fingerprint-not-recognised description: "K40 Pro says 'please try again' or rejects fingers? Clean the sensor, re-enrol, adjust the match threshold and handle dry, worn or wet fingers." updated: 2026-10-20 --- > Markdown copy of https://qyvea.co.ke/zkteco-k40-pro-fingerprint-not-recognised for AI assistants. Prices and stock change; check the live page. 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Most of it is cleaning and enrolment quality. [Shop ZKTeco K40 terminals →](https://qyvea.co.ke/products/zkteco-k40-fingerprint-time-attendance-terminal-67)[Get help on WhatsApp](https://wa.me/254113301244?text=Hi%20Qyvea%2C%20I%20read%20your%20guide%3A%20ZKTeco%20K40%20Pro%20Fingerprint%20Not%20Recognised%3A%20Causes%20and%20Fixes.%20I%20need%20help%20with%20my%20ZKTeco%20K40%20Pro.) Quick answer Clean the sensor with a soft dry cloth, re-enrol the finger on a different finger and with better technique, remind staff to press flat and firm, and keep the terminal away from direct sun and dust. **Buy your ZKTeco K40 from Qyvea**: Supplied and installed across Kenya. Delivered within 24 hours once payment is confirmed. [Shop ZKTeco K40 terminals →](https://qyvea.co.ke/products/zkteco-k40-fingerprint-time-attendance-terminal-67)[All attendance terminals](https://qyvea.co.ke/products?cat=biometrics&search=attendance)[Ask Qyvea on WhatsApp](https://wa.me/254113301244?text=Hi%20Qyvea%2C%20I%20read%20your%20guide%3A%20ZKTeco%20K40%20Pro%20Fingerprint%20Not%20Recognised%3A%20Causes%20and%20Fixes.%20I%20need%20help%20with%20a%20ZKTeco%20K40%20Pro.%20Please%20quote%20me.) ## Key takeaways - Clean the glass. - Re-enrol with good technique. - Enrol two or three fingers. - Avoid direct sun and moisture. ## Check the sensor - Wipe with a soft, dry, lint-free cloth. - Do not use harsh chemicals. - Look for scratches or oil build-up. - Keep it out of direct sunlight, which confuses optical sensors. ## Re-enrol badly enrolled fingers Delete the fingerprint and enrol again with a clean finger. See [enrol a fingerprint](https://qyvea.co.ke/zkteco-k40-pro-enroll-fingerprint). Press firmly and flat three times with the same angle. ## Difficult fingers - Dry skin: a light touch of moisture helps. - Wet or sweaty fingers: wipe dry. - Worn prints from manual work: use a different finger or consider face or card ([worn fingerprints](https://qyvea.co.ke/fingerprint-attendance-machine-not-reading-worn-fingerprints-kenya)). - Cuts and plasters: use a different finger. ## Other causes - Sensor damage after a knock or liquid spill. - Firmware issues; ask your supplier about updates. - Very hot or dusty rooms; protect the terminal. ## When to replace If cleaning, re-enrolment and a few staff all fail, the sensor may be worn. We can test it. [Message us on WhatsApp](https://wa.me/254113301244). ## A typical scenario A hardware shop's workers had rough, worn fingers and kept being rejected. Cleaning the sensor, enrolling three fingers each, and giving a short training solved most cases; two workers moved to card punching. *Illustrative example based on common cases, not a named customer.* ## Common mistakes - Cleaning with strong chemicals. - Enrolling once in a hurry. - Placing the terminal in sunlight. - Ignoring training. - Expecting every finger to work. ## Quick checklist 1. Clean the glass 2. Re-enrol 3. Two or three fingers 4. Check light 5. Train staff 6. Consider alternatives ## Frequently asked questions Why does it work for some staff only? Skin type, dryness and technique differ. Re-enrol and train. Can I make it more tolerant? Some firmware allows a match-threshold setting. Lower security equals easier matching but more false accepts; change with care. Do I need to clean it every day? A wipe each week is plenty; more in dusty sites. Is a face terminal better? For worn hands, yes. See [fingerprint or face](https://qyvea.co.ke/fingerprint-or-face-recognition-attendance-machine-kenya). This guide is part of our [ZKTeco K40 and ZKBio Time.Net series](https://qyvea.co.ke/zkteco-k40-zkbio-time-net-guides-kenya). For the full start-to-finish walkthrough with screenshots, read [How to Configure a ZKTeco K40 Pro with ZKBio Time.Net](https://qyvea.co.ke/how-to-configure-zkteco-k40-pro-zkbio-time-net). ZKTeco and ZKBio are trademarks of ZKTeco Inc. Menu names on the K40 Pro and in the software vary slightly by firmware and software version; where yours differ, look for the nearest match. Qyvea is a ZKTeco reseller and installer in Kenya. **Want us to do this for you?**: We supply, install, configure the software, enrol your staff and train your HR team. [Shop ZKTeco K40 terminals →](https://qyvea.co.ke/products/zkteco-k40-fingerprint-time-attendance-terminal-67)[All attendance terminals](https://qyvea.co.ke/products?cat=biometrics&search=attendance)[Ask Qyvea on WhatsApp](https://wa.me/254113301244?text=Hi%20Qyvea%2C%20I%20read%20your%20guide%3A%20ZKTeco%20K40%20Pro%20Fingerprint%20Not%20Recognised%3A%20Causes%20and%20Fixes.%20I%20need%20help%20with%20a%20ZKTeco%20K40%20Pro.%20Please%20quote%20me.) ## Why customers choose Qyvea **Genuine brands**: Manufacturer warranty on what we sell, so you are not gambling on the box. **One team, start to finish**: The people who advise you also install and support it. **Fast answers**: WhatsApp replies usually within 30 minutes, and delivery within 24 hours in Nairobi. **Easy to buy**: Pay by M-Pesa, bank transfer or card. Free delivery in Nairobi on orders over KES 5,000. **Risk taken off you**: 7-day returns and exchanges on products, and a workmanship warranty on installations. **Customers say so**: Rated 4.6/5 from 57 Google reviews. **Your next step takes one minute:** send us a photo of the place on WhatsApp and we will tell you what it needs. ## Related articles [Biometrics & Attendance · Troubleshooting ZKBio Time.Net SDK Error: zkemkeeper.dll Not Registered Reinstall or register the communication SDK so the PC can talk to the terminal. 2 min read**READ FULL ARTICLE →**](https://qyvea.co.ke/zkbio-time-net-sdk-zkemkeeper-error)[Biometrics & Attendance · Troubleshooting ZKBio Time.Net .NET Framework Error: Install and Fix Install or enable the .NET Framework the software needs, then reinstall. 2 min read**READ FULL ARTICLE →**](https://qyvea.co.ke/zkbio-time-net-dotnet-framework-error)[Biometrics & Attendance · Guide ZKBio Time.Net With Multiple Terminals and Branches Plan areas, IPs and one employee list for several terminals and branches. 2 min read**READ FULL ARTICLE →**](https://qyvea.co.ke/zkbio-time-net-multiple-devices-branches) ### Related guides [All ZKTeco K40 and ZKBio guides](https://qyvea.co.ke/zkteco-k40-zkbio-time-net-guides-kenya)[Configure a K40 Pro with ZKBio Time.Net](https://qyvea.co.ke/how-to-configure-zkteco-k40-pro-zkbio-time-net)[Use ZKTeco attendance software](https://qyvea.co.ke/how-to-use-zkteco-attendance-software) ### Related products [ZKTeco K40 terminal](https://qyvea.co.ke/products/zkteco-k40-fingerprint-time-attendance-terminal-67)[ZKTeco K40 price in Kenya](https://qyvea.co.ke/zkteco-k40-price-in-kenya)[ZKTeco attendance machines](https://qyvea.co.ke/zkteco-attendance-machine-price-in-kenya) ### Related services [Biometrics & attendance](https://qyvea.co.ke/biometrics)[Biometric attendance systems](https://qyvea.co.ke/biometric-attendance-systems-kenya) [← Previous**ZKTeco K40 Pro IP Address Conflict: How to Find and Fix It**](https://qyvea.co.ke/zkteco-k40-pro-ip-conflict)[Next →**: ZKTeco K40 Pro Showing Wrong Punch Times: Fix and Recover**](https://qyvea.co.ke/zkteco-k40-pro-wrong-time-punches) ## Need this system installed? 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