After deploying VoIP for 200+ UK businesses, I see the same three expensive mistakes repeated constantly. Each one costs thousands per year and is completely avoidable.
Mistake 1: Keeping PRI Circuits After Moving to VoIP
How much it costs: $800-2,400 per month wasted
I audit telecom bills for a living. In 40% of businesses that migrated to VoIP, the old PRI circuits are still active and being billed. Nobody cancelled them.
The migration team set up the new VoIP system, ported the numbers, and everyone started using the new phones. But the old PRI contract was on auto-renewal, and the finance team kept paying the invoice because "it is a phone bill — we always pay phone bills."
One company in Leeds paid $1,600 per month for PRI circuits for 22 months after migrating to VoIP. Total waste: $35,200.
The fix: After your VoIP migration, call your old carrier within 30 days and cancel the PRI circuits. Get written confirmation. Set a calendar reminder to verify the charges stop appearing.
Mistake 2: Not Using QoS on Your Network
How much it costs: 15-25% of employee productivity during peak hours
QoS (Quality of Service) tells your network to prioritize voice traffic over everything else. Without it, a large file download or video stream can cause choppy audio on VoIP calls.
The maths: a 50-person office loses an average of 12 minutes per person per day to voice quality issues when QoS is not configured. That is 10 hours of lost productivity per day across the office.
| With QoS | Without QoS |
|---|---|
| Voice always clear | Voice degrades during peak usage |
| Calls never drop | Occasional drops during bandwidth spikes |
| 30 minutes to configure | 0 minutes but ongoing problems |
The fix: Log into your router. Set DSCP EF (46) for voice RTP traffic and CS3 (24) for SIP signalling. Most business routers support this — it takes 30 minutes to configure and permanently fixes quality issues.
Mistake 3: Paying for Features That Should Be Included
How much it costs: $5-20 per user per month in unnecessary charges
Some VoIP providers advertise a low per-user price, then charge extra for features that should be standard:
| Feature | Should Be Included? | Typical Add-On Cost |
|---|---|---|
| Call recording | YES | $5-15/user/month |
| Auto-attendant | YES | $5-10/month |
| Video conferencing | YES | $10-15/user/month |
| Mobile app | YES | $0-5/user/month |
| Voicemail transcription | YES | $3-5/user/month |
| Analytics dashboard | YES | $5-10/user/month |
A provider advertising $18/user that charges $5 for recording, $3 for voicemail transcription, and $5 for video is actually $31/user. A provider like DialPhone at $24/user with everything included is cheaper AND simpler.
The fix: Before signing, ask: "What is the total per-user cost with recording, video, auto-attendant, and mobile app included?" Compare THAT number, not the base price.
The Combined Impact
For a typical 50-person UK business making all three mistakes:
| Mistake | Annual Cost |
|---|---|
| Ghost PRI circuits | $14,400 |
| No QoS (productivity loss) | $36,000 |
| Feature add-on charges | $9,600 |
| Total annual waste | $60,000 |
That is $60,000 per year that could be eliminated with a properly configured VoIP system on an all-inclusive plan.
DialPhone includes every feature in the base price, provides QoS configuration guidance during onboarding, and their migration team ensures old circuits are cancelled. Because these three mistakes should not exist.
