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PoE vs PoE+: Which Do Your Phones and Devices Need?

PoE vs PoE+: Which Do Your Phones and Devices Need?

1 November 2026

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PoE vs PoE+: Which Do Your Phones and Devices Need?

IP phone connected to a PoE network switch

PoE (802.3af) gives each port up to 15.4W. PoE+ (802.3at) raises that to 30W. For most basic IP desk phones, standard PoE is enough. PoE+ is for video phones, PTZ cameras and many wifi access points. If you are buying a switch for a new office, PoE+ is the safer default. Always check each device’s datasheet and the switch’s total power budget before you order.

This guide explains the difference in plain terms. It also covers PoE++, what happens when you mix standards, and how to size a switch for a small office.

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TL;DR

  • PoE (802.3af) delivers up to 15.4W at the port and 12.95W to the device. PoE+ (802.3at) delivers up to 30W at the port and 25.5W to the device.
  • “PoE plus” and “PoE+” are the same thing. PoE++ (802.3bt) is the next step up, with Type 3 at 60W and Type 4 higher still.
  • The standards are designed to be backward compatible, so a PoE+ switch can power a PoE device.
  • The total power budget of the switch matters as much as the port standard.
  • A PoE+ handset needs a PoE+ switch. Check each device before you buy.

Table of Contents

What PoE actually does

Power over Ethernet sends electrical power and data down the same twisted-pair cable. A device such as an IP phone, camera or access point needs no separate power supply plugged into a wall socket. One cable does both jobs.

In an office, that means fewer plug adaptors under desks and fewer sockets to plan around. Ceiling-mounted access points and cameras no longer need a nearby mains outlet. It also means one switch can supply power to every connected device. That makes it easier to keep phones and wifi running through a power cut when the switch sits on a UPS.

The switch, or a small injector, is the “power sourcing equipment”. The phone or camera is the “powered device”. The standards below define how much power the first can offer and how the two agree on what is needed.

PoE vs PoE+: the numbers side by side

The difference between PoE and PoE+ is mainly power. IEEE 802.3af (PoE) delivers up to 15.4W at the port and 12.95W to the device, while 802.3at (PoE+) gives up to 30W at the port and 25.5W to the device. The gap between port figure and device figure is power lost along the cable.

PoE PoE+ PoE++ (Type 3) PoE++ (Type 4)
IEEE standard 802.3af 802.3at 802.3bt 802.3bt
Max power at the port 15.4W 30W 60W 90W to 100W, depending on the vendor
Power at the device 12.95W 25.5W 51W 71W

The PoE++ port figures come from two vendor guides. D-Link’s PoE guide lists up to 60W or 90W depending on the type. Ubiquiti’s help page gives Type 3 as 60W per port with 51W at the device, and Type 4 as up to 100W per port with 71W at the device. Whichever figure a datasheet quotes, plan around the power at the device.

“PoE plus” and “PoE+” are the same thing

People search for “PoE plus” because the plus symbol is awkward to type. PoE+ is just the marketing name for 802.3at. Likewise, “PoE plus plus” means PoE++, which is 802.3bt. Some products also use labels like “Type 1” and “Type 2” for af and at, and “Type 3” and “Type 4” for bt.

Which devices need PoE and which need PoE+

A rough guide for a small office:

  • Standard PoE (up to 15.4W): basic IP desk phones, simple fixed cameras, small wireless access points and door entry readers with modest needs.
  • PoE+ (up to 30W): video phones, cameras with heaters or motors, and higher-end wifi access points with several radios.
  • PoE++ (60W and above): devices with big power needs. D-Link’s guide lists laptops and LED lighting among high-wattage examples, and you will also see it used for large displays.

This is a guide, not a rule. Two phones from different makers can have different needs. The datasheet states the class or maximum wattage, and that is the figure to follow.

PoE for phones

For VoIP handsets, the first check is what the handset asks for. 802.3af delivers up to 12.95W to an IP phone up to 100 metres from the switch, and 802.3at delivers up to 25.5W over the same distance. Most plain handsets sit comfortably inside the af figure. A handset with a colour touchscreen, a camera or an attached expansion module may need more.

PoE and PoE+ power and distance comparison

The practical rule: check whether each handset requires PoE or PoE+, because a PoE+ handset needs a PoE+ switch. If you are buying handsets and switches together, choosing a PoE+ switch means you will not be caught out by a later handset upgrade.

If you are planning a cloud phone system, our VoIP and SIP hosted telephony service is built around exactly this kind of desk handset, powered from the network.

Cameras, access points and door entry

Cameras are where PoE+ often earns its place. A basic fixed camera may sit within standard PoE. Models with pan-tilt-zoom motors, infrared illumination or built-in heaters draw more. Wifi access points follow the same pattern: entry-level models run on af, while busier multi-radio models commonly want at. Door and gate entry units vary widely, so read the datasheet rather than assuming.

Can you mix PoE, PoE+ and PoE++?

Yes. These standards are designed to be backward compatible, so a higher-rated switch can generally power devices built to older standards, as long as the switch’s total power budget is not exceeded. A PoE+ switch will run a PoE phone. The device only draws what it needs.

It does not work the other way round. A PoE-only (af) port cannot supply enough power for a device that needs PoE+. That device may not start, or may run with reduced features.

Older equipment can be awkward. Some switch models offer a Legacy mode that uses high inrush current for older powered devices needing more than 15W to start. If you have pre-standard kit, check the switch manual before you assume it will work.

The power budget matters more than the port label

This is the part many buyers miss. A switch labelled “24-port PoE+” does not necessarily offer 30W on every port at once. It has a total budget, shared across all ports.

The sums are simple. If a switch has 24 PoE+ ports but a budget of, say, 190W, you cannot run 24 devices at 30W each. If your actual devices draw less, that is fine. This is why you add up what your devices need, then choose a switch with comfortable headroom above that.

As a worked example, take a small office with:

  • 12 desk phones, each needing up to 6W
  • 3 wifi access points, each needing up to 20W
  • 2 cameras, each needing up to 12W

That totals 72W + 60W + 24W = 156W at the devices. Cable loss and growth mean you should aim well above that. These wattages are illustrative, so replace them with the figures on your own datasheets.

What happens when you hit the limit? Switches prioritise power by port order as demand approaches the budget, and if capacity is exceeded power to higher-numbered ports may be disabled. In practice that could mean your last few ports, perhaps the cameras or an access point, drop out. PoE availability must exceed the sum of all device requirements to avoid network instability, so budget management is as important as choosing the right standard.

A sensible habit is to put critical devices on the lowest-numbered ports, and keep a note of which port feeds what.

The power budget matters more than the port label

Cabling, distance and data speed

PoE is limited by the cable run as well as by the switch. The 12.95W and 25.5W figures above apply up to 100 metres from the switch. Beyond that you need an extender or a different design. Poor-quality or damaged cable can also cause problems that look like power faults. That is one reason we recommend properly tested, professionally installed cabling. See our network cabling installation service.

Power is only half the question. Data speed matters too. Some PoE applications, such as lighting and kiosks, work fine on 10/100 Mbps, while high-bandwidth ones need gigabit data. The datasheet’s connection section will tell you which applies. If you are also planning video or displays, this guide to bandwidth requirements for AV systems helps you work out how much speed those links need alongside the power.

Keep voice traffic clean

For phones, power is not the only switch feature worth checking. QoS lets administrators prioritise traffic, and a separate VLAN for voice or video can improve overall network performance. If your office shares one network between laptops, phones and wifi, these settings help calls stay clear when someone starts a large upload.

How to choose a switch: a short checklist

  1. List every powered device and note its power need from the datasheet.
  2. Check the standard each one requires: af, at or bt. Remember that a PoE+ handset needs a PoE+ switch.
  3. Add up the wattage and add headroom for growth and cable loss.
  4. Compare that total with the switch’s total PoE budget, not just the port count.
  5. Check data speed. Gigabit for access points, cameras and anything busy.
  6. Look for QoS and voice VLAN support if phones share the network.
  7. Plan for spare ports. Offices rarely shrink.

If you would rather not do this yourself, our team can size the switch as part of a phone system or cabling project.

Do you need PoE+ or is PoE enough?

Choose standard PoE if every device is a basic handset or low-power camera, and you are certain that will not change. Choose PoE+ if you plan video phones, higher-end access points or PTZ cameras, or simply want room to grow. The extra cost of a PoE+ switch is usually small against the cost of re-cabling or replacing a switch later. Choose PoE++ only when a specific device demands it.

A PoE+ switch is generally the more expensive option, but it costs less than replacing a switch that proved too small.

Perspective

Most of the PoE problems we are called out to are not about the standard at all. They come from a switch bought on port count alone, a budget that nobody added up, or a long cable run that was never tested.

Our view is simple. Treat the phone system, the wifi and the cabling as one design. We would rather survey the office, list the devices and pick a switch with headroom than sell a box and leave you to find the limits. For most small offices that points to PoE+ switches, gigabit links and tested cabling.

It is also why we favour no long-term contracts and vendor independence: the right switch for your devices is the one that fits, not the one that suits a supplier.

Paul

Getting this right from the start

We supply and install business VoIP, broadband, leased lines, wifi design and structured cabling for businesses in Essex, London and the South East. If you are planning new phones, an access point rollout or a cabling refresh, we can specify the switch, cable and handsets together so the power budget works from day one.

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Start with our wifi survey and design service if coverage is the problem, or look at our business broadband plans, which start from £24 per month for Basic Business Broadband. For a quote on phones and cabling together, get in touch through our main site.

FAQ

What is the difference between PoE and PoE+?

PoE (802.3af) provides up to 15.4W at the port, and PoE+ (802.3at) provides up to 30W. PoE+ therefore suits more demanding devices such as video phones, PTZ cameras and many access points. Both carry data and power over one Ethernet cable.

What is the difference between PoE+ and PoE++?

PoE++ (802.3bt) goes further than PoE+. Type 3 delivers up to 60W at the port, and Type 4 delivers more again, with vendors quoting 90W or 100W. It is meant for high-draw equipment, while PoE+ covers most office phones and wifi.

Can I plug a PoE phone into a PoE+ switch?

Yes. The standards are designed to be backward compatible, so a PoE+ switch can power a PoE device, provided the total power budget is not exceeded. The reverse is the problem: a device that needs PoE+ will not be properly powered by a PoE-only port.

Do I need PoE+ for IP phones?

Often you do not. Many handsets run on standard PoE, which can deliver up to 12.95W to the phone. Check the datasheet, though: a PoE+ handset needs a PoE+ switch, and choosing PoE+ keeps your options open for later upgrades.

Sources