What is a SIM-Only Deal? Complete UK Guide for 2025

A SIM-only deal is a mobile plan that gives you calls, texts, and data without a phone included. Here's everything you need to know.

SIM-Only Deal Basics

Unlike traditional phone contracts that bundle a handset with your plan, a SIM-only deal just covers your mobile service. You provide your own phone and only pay for: - Monthly data allowance - Calls and texts (usually unlimited) - Network access

How Much Can You Save?

SIM-only deals are significantly cheaper than phone contracts. Average savings: - Standard contracts: £30-50/month (includes phone repayment) - SIM-only: £5-15/month - Annual savings: £300-500

Who Are SIM-Only Deals For?

Perfect If You: - Already own a phone you like - Want to reduce monthly bills - Don't need the latest handset - Prefer flexibility with no long-term commitment - Buy phones outright or second-hand

Not Ideal If You: - Want a new phone and prefer spreading the cost - Don't own a compatible unlocked phone - Need device insurance included

Types of SIM-Only Plans

30-Day Rolling Contracts - Cancel anytime with 30 days notice - Maximum flexibility - Slightly higher monthly cost - Perfect for testing networks

12-Month Contracts - Lower monthly cost than 30-day plans - Still cheaper than 24-month phone contracts - Good middle ground for commitment

What's Included?

Most UK SIM-only deals include: - Unlimited calls and texts (standard on all modern plans) - Data allowance (ranges from 1GB to unlimited) - EU roaming (varies by provider) - 5G access (on compatible networks and phones) - No credit check options (available from some providers)

Understanding Data Allowances

Choose your data based on usage: - 1-5GB: Light users, mostly on WiFi - 10-20GB: Moderate users, social media, browsing - 30-50GB: Heavy users, streaming, video calls - Unlimited: Constant streaming, mobile hotspot use

See our guide on understanding data allowances for more details.

Network Coverage Matters

Before choosing a deal, check coverage: - EE: Best overall UK coverage - Vodafone: Strong urban coverage - Three: Good value, improving coverage - O2: Priority access to O2 WiFi hotspots

Budget networks (Smarty, giffgaff, Voxi, Lebara) use these main networks at lower prices. Check UK mobile network coverage for your postcode.

Making the Switch

Switching to SIM-only is simple: 1. Check your current contract status 2. Choose a new deal from our best SIM only deals 3. Request a PAC code to keep your number 4. Insert new SIM and activate

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Bottom Line

SIM-only deals offer: - Lower costs than phone contracts - Flexibility to change plans easily - No wasted money on phone subsidies - Freedom to upgrade your phone whenever you want

If you already have a phone, there's no reason to pay for one you don't need.

Ready to find your perfect SIM-only deal? Browse our curated selection of the best current offers.