There are only four mobile networks in the UK that own masts. There are dozens of brands selling mobile service. Every one of those brands is running on somebody else's network, and which one decides whether your phone works at your site. Knowing how to tell them apart is the difference between buying coverage and buying a logo.
The 30-second version
- Only a handful of operators own the masts. Everyone else rents access to them.
- An MVNO is a brand running on a host network. Coverage comes from the host, not the brand.
- "Piggyback" is the informal name for this, and it is not a criticism. Plenty of MVNOs are excellent.
- What can differ is priority, speed caps and roaming, even on identical coverage.
- Ask one question before buying: whose network does this run on?
- A multi-network SIM is a different thing entirely. It uses more than one host rather than renting from one.
On this page
Who actually owns the masts
Building and running a mobile network is enormously expensive, so very few organisations do it. The companies that own the physical infrastructure are called mobile network operators. Everyone else is a customer of one of them.
That is why two brands with completely different names, prices and advertising can deliver exactly the same signal in your building. They are using the same masts.
At Synergy Max we supply Vodafone, O2 and EE, and we choose between them based on where a customer actually works rather than where their head office is.
What an MVNO really is
MVNO stands for mobile virtual network operator. It is a brand that sells mobile service without owning any masts, by buying wholesale access from one that does.
This is a completely legitimate model and some MVNOs offer excellent value. The thing to understand is simply where the coverage comes from:
- Coverage is the host's. If the host network is poor at your premises, the MVNO will be poor at your premises. No tariff fixes that.
- The brand you recognise may not be the network you get. Several well known names are MVNOs.
- Hosts can change. An MVNO can move from one host network to another, and your coverage changes with it, usually without much fanfare.
Why this matters more for business than for personal use
At home you find out quickly whether the signal works and you can change your mind cheaply. Across a fleet of twenty phones on a three year term, discovering that the host network is weak at your main depot is an expensive thing to learn late.
Same coverage, different experience
Two SIMs on the same host network are not automatically identical. The host's own customers and the MVNO's customers can be treated differently.
| What can differ | What it means in practice |
|---|---|
| Traffic priority | When a cell is congested, host customers may be served ahead of wholesale traffic. You notice this at busy times and in crowds, not at 10am on a Tuesday. |
| Speed caps | Some wholesale deals cap maximum speed, so the same mast gives you less than it gives the host's own customer. |
| 5G access | Not every wholesale agreement includes 5G, or includes all of it. |
| Roaming | Roaming arrangements are negotiated separately and are often narrower than the host's own. |
| Support and provisioning | Porting, new lines and fault escalation go through the brand, not the host, which affects how quickly things get done. |
None of that makes MVNOs a bad choice. It makes "it is on EE" an incomplete answer rather than a complete one.
How multi-network SIMs differ
This is where people conflate two different things. An MVNO rents from one host network. A multi-network SIM can use more than one network, selecting whichever has usable signal at that location.
The practical difference is what happens in a weak spot. On a single network SIM, MVNO or otherwise, a weak spot is a weak spot every day. On a multi-network SIM the device can move to another network instead.
That makes multi-network SIMs genuinely useful for devices and people that move across a mixed patch, and largely unnecessary for a team that works in one place with known good coverage. We cover the detail in multi-network SIM pros, cons and best uses and the speed question in multi-network versus single network on 4G and 5G.
What to ask before you buy
- "Whose network does this run on?" One question, and it should get a straight one word answer. Hesitation is informative.
- "Is it full access or is anything capped?" Speed caps and partial 5G access are worth knowing before signing, not after.
- "What happens if you change host network?" Ask what notice you get and what you can do about it.
- "Does roaming match the host's?" If anyone travels, check rather than assume.
- "How is coverage at these specific postcodes?" Your sites, not your office. Our post on kit in the field covers why the office is the wrong test.
Not sure what you are actually on?
Send us a bill and the postcodes your people work at. We will tell you which network is really carrying your traffic, whether it is the right one for those locations, and whether anything is capped.