Top 7+ Common Reasons Why RFID Tags Fail to Scan (and How to Fix Them)

Introduction

RFID (Radio Frequency Identification) technology has become an indispensable solution across various industries such as logistics, warehousing, retail, manufacturing, education, and healthcare. Using RFID tags enables businesses to manage assets, personnel, and goods more quickly and accurately. However, in actual deployment, many users encounter situations where RFID tags cannot be scanned, causing operational disruptions and directly impacting work efficiency.

So, why do RFID tags fail to be read, even when the system appears to be functioning properly? This article will provide a detailed analysis of the 7+ most common causes, along with specific solutions for each scenario—helping you save time, reduce costs, and minimize risks when implementing RFID systems.

How Does RFID Work?

To understand why an RFID tag is not readable, we first need to grasp the basics of RFID operation:

• RFID Tag: Consists of a chip and an antenna, available in active (battery-powered) or passive (no battery) versions.

• RFID Reader: Sends a radio signal to the tag, which then responds with encoded information.

• Frequency Bands: RFID operates on several frequency bands: LF (125–134 kHz), HF (13.56 MHz), and UHF (860–960 MHz).

• Read Range: LF/HF tags typically offer ranges under 1 meter, while UHF tags can reach up to 10–15 meters depending on power and environment.

Common Reasons Why RFID Tags Fail to Scan

Physically Damaged RFID Tags

Issue Description:
The tag is bent, cracked, or exposed to harsh conditions, damaging the internal chip or antenna.

How to Check:

• Use another reader or UID-checking software to test the tag.

• If none of the readers can detect the tag, it’s likely damaged.

Solution:

• Replace the tag.

• Use encapsulated RFID tags for rugged or industrial environments.

Incorrect Distance or Scan Angle

Issue Description:

• The user positions the tag too far or too close to the reader.

• The tag is not aligned with the main signal area or is angled incorrectly.

Solution:

• Place the tag within the optimal scanning range recommended by the device (typically 3–10 cm for HF, 1–5 m for UHF).

• Rotate the tag so that its antenna is parallel with the reader’s signal direction.

Interference from Metal or Liquids

Issue Description:
RFID signals are easily absorbed or reflected by metal and weakened by liquids. Tags attached to metal surfaces, machinery, or liquid containers are more difficult to scan.

Solution:

• Use anti-metal RFID tags for metal surfaces.

• In humid environments, use waterproof tags or mount tags outside of liquid containers.

Incompatible Frequency Between Tag and Reader

Issue Description:
An HF tag is used with a UHF reader or vice versa, causing a frequency mismatch.

Solution:

• Check the technical specifications: HF tags (13.56 MHz) require HF-compatible readers (e.g., NFC).

• UHF tags (860–960 MHz) must be used with UHF readers.

• Never mix different RFID frequency types.

RFID Reader Hardware or Firmware Malfunction

Issue Description:
The RFID reader is not receiving power, loses network connection, or runs on outdated firmware.

How to Check:

• Inspect power sources and status indicator lights.

• Use test software or RFID management tools to check the reader’s connection.

Solution:

• Update the reader’s firmware.

• Check drivers and communication protocols (USB, COM, TCP/IP).

• Ensure stable connectivity, especially for cloud-based readers.

Corrupt or Unprogrammed Tag Data

Issue Description:
The tag is blank or hasn’t been encoded with an EPC or UID. Data may be in an incorrect format.

Solution:

• Use RFID Writer software to encode the tag.

• Ensure the data follows the correct format: EPC GEN2 (for UHF) or ISO/IEC 14443 (for HF).

• If using encryption, configure the correct key before attempting to read the tag.

Software Not Properly Connected to Reader

Issue Description:
The reader works, but the data doesn’t appear in the software.

Possible Causes:

• Incorrect COM/IP port settings or unactivated API.

• Missing drivers or permission issues.

Solution:

• Install all required drivers.

• Set up the correct ports and protocols.

• Use official software provided by the supplier (e.g., Beetech’s UHF reader application).

Non-Optimized Deployment Environment

Real-Life Example:
Warehouses with multiple RF-transmitting devices (walkie-talkies, Wi-Fi routers) can cause RFID interference. Tags placed too closely (tag collision) make it difficult for the reader to identify them individually.

Solution:

• Reduce the number of tags being read simultaneously if anti-collision tech isn’t in use.

• Position readers in open areas, away from strong signal emitters.

Common Mistakes When Implementing RFID Systems

• Choosing low-cost tags that don’t match environmental requirements (e.g., using paper tags in industrial settings).

• Ignoring software–hardware–tag compatibility.

• Overlooking physical challenges such as metal surfaces, walls, or interference.

• Failing to train staff to regularly inspect and maintain the RFID system.

Recommended System Checks When Tags Fail to Scan

Contact Beetech for Expert RFID Support

Beetech is a leading RFID solution provider in Vietnam offering end-to-end services including:

• Various RFID Tags: Paper, anti-metal, epoxy, wristband, and more

• Fixed & Mobile Readers: Ideal for logistics, production lines, libraries, and healthcare

• Custom RFID Software: Fully integrable with ERP, POS, CRM, or custom systems

• Nationwide Technical Support: Site surveys – Installation – User training

Why Choose Beetech?

✅ Over 10 years of hands-on RFID deployment experience
✅ Expert engineers in both hardware and software
✅ Competitive pricing with all-inclusive packages
✅ 24/7 remote and onsite technical support
✅ Authorized distributor of Zebra, Unitech, Alien, Impinj…

👉 Having trouble scanning RFID tags?

Contact Beetech today for:

• A free RFID system check-up

• Expert advice on choosing suitable tags and readers

• Optimized RFID solutions for warehouse, retail, and traceability management

📧 Email: info@beetech.com.vn
🌐 Website: https://beetech.com.vn