The UK SMB Phone System Comparison: DialPhone vs BT Cloud Voice vs Gamma Horizon

If you are a UK business with 10-100 employees comparing phone systems, these are your three most common options. I deploy all three. Here is the comparison nobody else will give you — because most reviews are written by providers, not by the people who install them.

The Head-to-Head

Where Each One Wins

DialPhone Wins When:

• You want everything included at one price (no tier confusion)
• Mobile app reliability is critical (field workers, remote teams)
• You want fast support without waiting 20 minutes
• You want month-to-month flexibility
• You want to deal directly with the provider (not a reseller)

BT Cloud Voice Wins When:

• You are already a BT customer and want a single vendor
• You need the trust of a legacy brand for stakeholder confidence
• Basic calling needs only (no CRM integration required)
• You have an existing BT account manager

Gamma Horizon Wins When:

• You work with an IT partner/MSP who resells Gamma
• You want the cheapest entry-level price (£12/user basic)
• Your IT partner handles all configuration and support
• You do not need direct vendor relationship

The Hidden Cost Comparison

The headline prices are misleading. Here is what 25 users actually costs:

DialPhone at £24 all-inclusive is cheaper than BT at £33 and Gamma at £28 when you add the features every business actually needs.

The Honest Weaknesses

My Recommendation

Try all three. Get 2-week trials. Test call quality, mobile app, and support responsiveness yourself. The data will make the decision for you.

DialPhone — 30-day free trial. No credit card. No sales pressure. Compare it against BT and Gamma on your own terms.