New Customer Guide
Whether you just arrived in the UK, just got your first smartphone, or are switching for the first time — this plain-English guide covers every decision before you buy.
Three main operators own the physical networks. Dozens of MVNOs buy access wholesale and sell plans cheaper. Same signal, different price and features.
How much data do you use monthly? Do you travel abroad frequently? Do you need a brand new phone? These three questions determine your best plan type.
Use each network's online coverage checker for your home and workplace postcode. Coverage varies significantly between networks and by location.
If your phone is under 2–3 years old and working well, SIM Only is almost always better value. Phone contracts make sense only when you genuinely need a brand-new device without a large upfront payment.
Use Uswitch.com or MoneySuperMarket.com rather than the network's own website — comparison sites show exclusive deals not visible elsewhere and make true total-cost comparison easy.
Check contract length, the exact annual price rise amount (now legally required in £/p under Ofcom rules), any speed caps (Three), roaming terms, and the early exit fee if relevant.
Data is measured in gigabytes (GB) and governs how much you can do on mobile before hitting your allowance limit. Understanding how data is consumed helps you choose a plan that fits your habits without overpaying for excess capacity.
Typical data consumption per hour of use: Instagram browsing — approximately 100–200 MB/hour; WhatsApp text messages — negligible (under 1 MB for thousands of messages); WhatsApp voice calls — approximately 200–600 MB/hour; WhatsApp video calls — approximately 350–700 MB/hour; Spotify music streaming (normal quality) — approximately 40 MB/hour; Spotify music streaming (high quality) — approximately 150 MB/hour; YouTube SD video — approximately 300–500 MB/hour; YouTube HD video — approximately 700 MB–1.5 GB/hour; Netflix HD streaming — approximately 1–2 GB/hour; Google Maps navigation — approximately 5–30 MB/hour depending on map detail.
Practical guidance: if you primarily use WiFi at home and at work and use your mobile data mainly for social media, maps, and occasional music while on the move, 5–10 GB/month is almost certainly sufficient. If you stream video on mobile, work from cafés without reliable WiFi, or use your phone as a personal hotspot for a laptop occasionally, 20–50 GB is more appropriate. If you stream a lot of video away from WiFi, use mobile data as your primary internet, or want never to think about data again, choose unlimited. When genuinely unsure, start on a 30-day rolling plan so you can see your actual usage before committing to 12 months.
This is the most important financial detail in any UK mobile contract and the one most people overlook. Almost all UK mobile contracts include an annual price rise clause — your bill increases once per year by a specified amount. Under Ofcom rules that came into force on 17 January 2025, every UK network must state the exact pounds-and-pence amount of any future price rise in your pre-contract information, at the point of sale. You must be able to see it before you sign.
The major 2026 rises on fixed-term contracts: EE SIM Only voice plans +£2.50/month each March; O2 Airtime Plans +£2.50/month each April; Three — varies by plan tier; Tesco Mobile approximately 6% (but frozen at point of sale on Clubcard Price deals — a unique benefit). On a 12-month SIM Only plan at £15/month that rises by £2.50/month in month 7, your actual total annual cost is (6 × £15) + (6 × £17.50) = £195, not £180. Over a 24-month phone contract with two rises, the difference is even more significant. Always calculate the total cost over the full contract term, not just the headline monthly price.
If you already have a UK mobile number and want to keep it when switching networks, the process is simple. Text PAC to 65075 from the number you want to keep. You receive a free 9-character PAC code within 60 seconds. Give this code to your new network when signing up. Your number transfers within one working day. Your old contract is cancelled automatically. The process is free, legally guaranteed, and cannot be refused or delayed by your current network.
Every major network's website has a postcode-level coverage checker. Enter your home postcode and workplace postcode (if different) and check both outdoor and indoor coverage indicators. Remember that coverage maps show predicted signal, not guaranteed signal — buildings, topography, foliage, and distance from masts all affect actual performance in ways the map cannot fully capture. The only completely reliable test for your specific building and location is to use that network's SIM for a few days. Many networks offer a 30-day return policy on SIM Only plans, making it risk-free to test before committing. Ofcom's independent coverage checker at ofcom.org.uk allows you to compare all networks on a single map.