VoIP hardware looks simple until the install day: the handset is right, but the platform is wrong; the desk has no PoE; the headset connector does not match; or a legacy alarm line was assumed to be just another phone.
For v1, Business IT Supply treats comms as a guided hardware category, not a telco service. We can help you buy phones, headsets, PSUs, PoE gear, DECT and UPS coverage with honest stock. We do not imply that hardware alone makes emergency calling, SIP trunking, number porting, calling plans, tenant readiness or service uptime work.
Start with the platform
Choose the platform first, then the phone.
| Platform | Hardware rule | Quote-first when |
|---|---|---|
| Microsoft Teams | Use Teams-certified models only when certification is explicit. | Tenant configuration, emergency locations, provisioning or 10+ handsets are involved. |
| 3CX | Match the phone model and provisioning mode to the supported list. | Provisioning, router/firewall assumptions, remote users or multi-site rollout. |
| Generic SIP | Check that the phone supports the features your PBX/provider actually uses. | SIP trunks, number porting, calling plans, fax/ATA or provider configuration are in scope. |
| Not sure | Do not buy by brand alone. Start with users, sites, power and dependencies. | Any lift, fire, medical, alarm or fax line touches the project. |
The most common mistake is treating “SIP” as a universal compatibility promise. It is not. It is a useful starting point, but codec support, provisioning, BLF keys, firmware, NAT behaviour and provider rules still matter.
Pick the phone type
Desk phones suit fixed users, reception, shared desks and warehouses. Check display size, line keys, gigabit passthrough, headset ports, WiFi/Bluetooth and whether a PSU is included.
DECT cordless suits roaming staff inside one small site. Single-cell DECT is simple. Multi-cell DECT is quote-first because roaming, coverage and handover need design.
Conference phones need platform support checked carefully. USB, SIP and Teams-room style devices are different buying paths.
ATA/fax adapters are quote-first. Fax, alarm, lift, fire and medical dependencies should not be treated as ordinary phone extensions.
Headsets need connector matching. Check RJ9, USB, Bluetooth, DECT, EHS cable and answer/hang-up support for the exact phone model.
Power: PoE or PSU
Most business IP phones are best powered by PoE, but that means the switch must have enough ports and enough total PoE budget. Do not count only handsets: WiFi access points, cameras and door devices may be using the same budget.
If a desk does not have PoE, order the matching PSU. Many phones either do not include one or have different adapter requirements by model. A phone that arrives without power is not a stock problem; it is a kit-design problem.
Use the PoE switch guide when phones share switching with access points, and size the switch with headroom.
Accessory checklist
Before ordering phones, check:
- PoE switch port or injector per handset.
- Matching PSU where PoE will not be used.
- Headset connector and user workflow.
- Wall mount for reception, warehouse, kitchen or corridor phones.
- Expansion module for reception or high-key-count users.
- Patch leads and cable path to the desk.
- UPS coverage for modem/router, firewall, PoE switch and any voice-critical hardware.
UPS does not create service uptime by itself, but it prevents a local power outage from immediately dropping powered voice/network equipment. For network runtime planning, use the UPS sizing guide.
Quote-first boundaries
Self-serve hardware is fine for a small, known-platform desk-phone top-up. Quote review is the correct path when the order touches:
- 10 or more handsets.
- More than one site.
- 3CX or Teams provisioning.
- Multi-cell DECT.
- SIP trunking.
- Number porting.
- Calling plans.
- Tenant configuration.
- Lift, fire, medical, alarm or fax dependencies.
Those triggers are not upsell theatre. They are where the risk moves from “buy the right device” to “make the voice environment work”.
Australian caveats
Triple Zero and IPND obligations sit with the carriage/service configuration, not with a handset in isolation. Teams emergency calling can be location and tenant dependent. NBN and local power outages can affect voice availability. If a phone project has life-safety, compliance or legacy-line dependencies, treat it as quote-first and document what service provider, site and power assumptions are being made.
How to buy from BIS
For small hardware orders, browse Comms & VoIP, add confirmed lines to a quote, and use the product stock ledger to see verified stock separately from supplier ETA and CALL. CALL is never counted as available.
For anything quote-first, send the site count, platform, handset count, headset needs, PoE/PSU plan, and any lift/fire/alarm/medical/fax dependencies. We will review the hardware list before money changes hands.
