Cat5e vs Cat6 for Business Cabling: Which Do You Need?

Short answer: if you are running new cable, use Cat6. If you already have Cat5e in good condition, you probably do not need to rip it out. Here is why.

The Practical Differences

When Cat5e Is Fine

• It is already installed, in good condition, and tested
• Your devices only need 1Gbps (most office PCs, VoIP phones, basic printers)
• PoE devices are low-power (standard IP phones, basic access points)
• Cable runs are short (under 50 metres)
• You are not planning high-density Wi-Fi or 4K CCTV in the near future

If your building already has Cat5e and it passes a cable test, do not let anyone tell you it all needs replacing. It supports 1Gbps Ethernet and standard PoE perfectly well. The cost of ripping out and replacing working cable is rarely justified unless there is a fault.

When You Should Use Cat6

• Any new cable run the price difference per metre is small and the performance headroom is significant
• Wi-Fi access points drawing PoE+ modern high-performance APs (like Omada EAP670 or UniFi U6 Enterprise) draw up to 25W. Cat6 handles this more reliably over longer runs.
• 4K CCTV cameras higher bandwidth cameras benefit from Cat6's better noise rejection, particularly on runs over 50 metres
• Runs over 50 metres Cat6 maintains better signal integrity at longer distances
• Environments with electrical interference offices with lots of fluorescent lighting, near lift shafts, or running parallel to mains power cables
• Server rooms and switch uplinks where you might want 2.5G or 10G connections in future

What About Cat6a?

Cat6a supports 10Gbps over the full 100 metres (where Cat6 only does 10Gbps to about 55 metres). It is thicker, more expensive, and harder to work with in tight spaces. For most small business installations, Cat6 is the right choice. Cat6a makes sense in server rooms, data centres, or buildings where you know you will need 10Gbps to every desk within the next few years.

Common Mistakes

• Replacing working Cat5e "just because" if it tests fine, it works fine. Spend the money on things that actually improve performance (more access points, better switching, QoS configuration).
• Using Cat5e for new PoE+ devices it can work, but Cat6 is more reliable for higher-power devices on longer runs. The cost difference for a new install is negligible.
• Mixing Cat5e patch leads with Cat6 infrastructure your cable run is only as fast as its weakest link. If you install Cat6 structured cabling, use Cat6 patch leads too.
• Forgetting that the termination matters badly terminated Cat6 performs worse than well-terminated Cat5e. The cable is only as good as the installation.

Our Recommendation

For any new cabling installation in Northern Ireland, we use Cat6 as standard. The material cost difference is small (typically 10-20% more per metre), and it gives you headroom for PoE+ devices, higher-bandwidth applications, and anything that comes along in the next 10-15 years of that cable's life in the wall.

If you have existing Cat5e, we test it before making any recommendation. Good Cat5e stays. Damaged or unterminated cable gets replaced with Cat6.

Cabling Is Only Part of the Setup

Good cabling helps, but the network still needs to be designed, documented and supported. We can install Cat5e or Cat6 cabling, then help maintain the Wi-Fi, switches, CCTV, VoIP phones, routers and firewall that depend on it.

• Managed IT and telecoms support contracts
• Business Wi-Fi installation Northern Ireland
• Managed firewall and threat prevention NI
• VoIP support Northern Ireland