SMARTY keeps its prices low by offering simple SIM-only plans, operating mainly online and using the existing Three mobile network rather than building a separate network of its own.
Its plans run on a one-month rolling basis, with no handset included and no annual contractual price rises. This gives SMARTY fewer costs to recover than a traditional mobile contract that includes a new phone, high-street shops and telephone-based support.
That does not mean SMARTY is automatically the best network for everyone.
The lower price comes with trade-offs, including online customer service and reliance on Three’s coverage in the places where you use your phone.
I have used SMARTY for several years as a low-cost second mobile service.
You can join through my referral link below:
Join SMARTY using my referral link
If the referral qualifies, you and I both receive the current SMARTY reward.
Why is SMARTY so cheap compared with other networks?
SMARTY has a simpler business model than many large mobile providers.
It mainly sells:
- SIM-only plans
- One-month rolling plans
- Online account management
- Plans without a handset
- A relatively small range of straightforward options
SMARTY does not need to recover the cost of supplying an expensive phone as part of your monthly payment.
It also describes itself as a fully online service. Support is mainly provided through its Help Centre, app, web chat and email rather than a network of high-street shops or a standard customer-service phone line.
These choices reduce overheads and help SMARTY compete on monthly price.
Is SMARTY owned by Three?
Yes. Three owns SMARTY, and both brands use the same mobile network.
This means SMARTY does not need to build and maintain an entirely separate national network.
It uses Three’s 4G and 5G infrastructure while selling its own plans, managing its own customers and using the SMARTY brand.
Three UK and Vodafone UK completed their merger in June 2025. SMARTY customers remain on a service powered by Three, with longer-term network integration and investment taking place under VodafoneThree.
The price may be lower than Three’s own headline plans, but that does not mean SMARTY receives a completely different signal.
Your experience will still depend heavily on Three network coverage and capacity in your area.
Does SMARTY have the same coverage as Three?
SMARTY uses the Three network, so its underlying coverage is based on Three’s 4G and 5G infrastructure.
However, mobile coverage is never identical in every location or building.
Signal strength and data speed can be affected by:
- Distance from the mast
- Local terrain
- Building materials
- Indoor location
- Network congestion
- Whether 4G or 5G is available
- Your phone and its supported frequency bands
Check the SMARTY coverage map for your home, workplace and other regular locations before switching.
A cheap mobile plan is not good value if the signal is unreliable where you need it.
Is SMARTY slower than Three?
SMARTY provides access to 4G and 5G through the Three network.
SMARTY says its plans are 5G-ready at no extra cost, and it does not advertise a general speed restriction on its standard unlimited plan.
That does not guarantee a particular speed.
Actual performance depends on local coverage, congestion, signal quality, the phone being used and the technology available from the nearby mast. SMARTY’s own guidance says estimated maximum speeds are not guaranteed in every place or environment.
In practice, SMARTY can be very fast in an area with strong Three coverage and much weaker somewhere the Three signal is poor.
Does SMARTY have annual price rises?
SMARTY says its rolling one-month plans do not have annual contractual price rises.
That is different from many longer mobile contracts where the monthly charge increases automatically each year.
However, it does not mean SMARTY can never change its prices.
Because the plans renew monthly, SMARTY can withdraw a plan or change the price offered for future months, subject to its terms and any notice it must provide.
The practical benefit is that you are not tied into a long contract if the price or service stops working for you.
Are SMARTY plans really one-month contracts?
SMARTY plans operate on a rolling monthly basis.
You can normally change, pause or cancel your plan without being tied into a 12, 18 or 24-month mobile contract.
This is one reason the service is attractive for:
- A second phone
- A child’s phone
- Temporary mobile data
- Testing Three coverage
- A mobile broadband router
- Someone who does not want a long contract
- People whose data needs change regularly
If you join through a referral link, remain active long enough to meet the referral conditions before cancelling or pausing.
Does SMARTY include unlimited calls and texts?
SMARTY’s standard phone plans generally include unlimited UK calls and texts, with the monthly price mainly changing according to the data allowance.
This keeps the plans simple.
You are usually choosing between different data levels rather than calculating separate call and text allowances.
Check the current plan details before ordering, especially for data-only products or specialist offers.
Does SMARTY include 5G?
Yes. SMARTY provides 5G access on compatible plans and devices where Three’s 5G network is available.
There is not normally a separate 5G surcharge.
To use 5G, you need:
- A 5G-compatible phone
- A SMARTY plan that supports the service
- 5G coverage in your location
- The correct phone settings
Your phone will generally fall back to 4G where 5G is not available.
What is the catch with SMARTY?
There is no single hidden catch, but the lower-cost model will not suit everybody.
The main compromises are:
Customer service is mainly online
SMARTY support is provided through its Help Centre, app, web chat and email.
This may suit people who are comfortable managing an account online.
It may be less suitable if you prefer calling a customer-service number or visiting a shop when something goes wrong.
Coverage depends on Three
If Three has weak coverage in your area, SMARTY is unlikely to solve that problem.
Always check local coverage rather than relying on national population percentages.
It is mainly SIM-only
SMARTY is best known for plans where you provide your own phone.
If you want a new handset bundled into a long-term contract, another provider may offer a more suitable package.
Roaming has limits
SMARTY includes use in eligible European destinations, but its current fair-use policy limits included EU data to 12GB per month. Further data may require an add-on.
A rolling plan is not a permanent price guarantee
The lack of an annual contractual rise is useful, but a one-month arrangement does not promise that the same plan and price will remain available forever.
Is SMARTY good for roaming?
SMARTY currently allows customers to use eligible plans in supported European destinations.
Calls and texts work within the applicable roaming terms, while included EU data is subject to a 12GB monthly fair-use limit.
This may be enough for a normal holiday but could be restrictive for:
- Long trips
- Heavy video streaming
- Remote working
- Using a phone as a hotspot
- Customers with very large UK data allowances
Roaming outside the included European destinations is charged separately.
Check the current country list, rates and fair-use terms before travelling.
Is SMARTY good for unlimited data?
SMARTY offers an unlimited data plan with unlimited UK calls and texts.
SMARTY states that its UK unlimited plan does not have a general fair-use data cap, although normal terms and acceptable-use rules still apply.
An unlimited plan may make sense for:
- Heavy phone data use
- Tethering
- Temporary home internet
- A compatible 4G or 5G router
- Locations where Three has strong coverage
Before relying on it for home broadband, test the signal and speed at the exact location where the router will sit.
Mobile performance can vary during the day as network demand changes.
Does SMARTY offer Wi-Fi Calling?
SMARTY includes Wi-Fi Calling on supported devices.
This can help with calls and texts inside a building where the mobile signal is weak but a reliable Wi-Fi connection is available.
Check device compatibility before joining, particularly if Wi-Fi Calling is needed at home.
It should not be treated as a replacement for checking outdoor and mobile coverage in the places where you travel.
Can I keep my existing mobile number?
Yes. You can transfer an existing UK mobile number to SMARTY using a PAC from your current provider.
SMARTY provides an online process for submitting the PAC and moving the number.
Keep your old service active until the transfer has completed.
There may be a short period on the transfer day when calls, texts or data are interrupted.
Who is SMARTY best for?
SMARTY may suit you if you want:
- A low-cost SIM-only plan
- A one-month rolling arrangement
- No scheduled annual contractual price rise
- Unlimited UK calls and texts
- 4G and 5G access
- A large data allowance
- Online account management
- The option to change or cancel without a long contract
- Access to the Three network
It may be less suitable if:
- Three coverage is poor where you live
- You want telephone or shop-based support
- You need a new phone included
- You use more than the EU roaming allowance
- Another network performs better in your area
- You want a long fixed-price guarantee
Is SMARTY worth it?
SMARTY can be very good value where the Three network performs well.
The low monthly price is not created by removing basic mobile features. It comes mainly from the SIM-only, online and rolling-plan business model.
The most important test is coverage.
A more expensive network may still be better value if it gives you reliable service in places where SMARTY does not.
My view is that SMARTY works best as a straightforward, flexible service for people who are comfortable managing their mobile account online.
The one-month plan also makes it relatively easy to try without taking on a long contract.
Join SMARTY through my referral link
If you have checked the coverage and decided SMARTY suits you, you can join using my referral link:
Join SMARTY using my referral link
The SMARTY Refer a Friend scheme gives both the new customer and the person who referred them a reward after the qualifying conditions have been met.
The reward value depends on the price of the qualifying plan.
You can read the full details here:
Referral disclosure
If you join SMARTY through my referral link and meet the qualifying conditions, you receive the advertised reward and I receive the same amount.
You will not pay more for using my link.
The referral income helps cover the cost of running Energy Stats UK and producing my independent articles, data and videos.
SMARTY can change its plans, prices, roaming terms and referral conditions. Check the current information before joining.