SIM only vs pay monthly vs pay as you go: which mobile plan is right for you?

Choosing the right mobile plan can save you hundreds of pounds annually whilst ensuring you have the coverage and data you actually need. With SIM only deals, pay monthly contracts, and pay-as-you-go options all available, understanding the difference between SIM only and pay-as-you-go plans, plus how they compare to traditional contracts, helps you make the smartest choice for your budget and lifestyle.

A quick comparison between SIM plans

SIM only deals provide just the SIM card and mobile service without a phone included. You'll need your own handset, but monthly costs are significantly lower. Contract lengths typically range from 30 days to 24 months, with prices reflecting your commitment period.

Pay monthly contract: Bundle a new phone with your mobile service. You're essentially paying for the handset in instalments alongside your airtime, resulting in higher monthly costs but spreading the phone's price over 24-36 months.

Pay as you go (PAYG) requires no contract commitment. You top up credit as needed and only pay for what you use. There's no monthly bill, but per-minute, per-text, and per-MB rates are typically higher than contract prices.

What is the difference between SIM only and pay as you go?

The fundamental difference between SIM only and pay as-you-go lies in commitment and payment structure. SIM only plans involve monthly contracts with fixed allowances, whilst PAYG operates on prepaid credit without contracts.

How SIM only deals work

SIM only contracts provide a monthly allowance of minutes, texts, and data for a fixed price. You commit to a contract length (typically 30 days, 12 months, or 24 months), and your allowance renews each month. You're billed automatically via direct debit.

The advantage? You know exactly what you're paying each month, your allowances are generous, and longer contracts offer better value. The commitment means you can't simply stop service without notice, though 30-day rolling contracts provide flexibility.

How pay as you go (PAYG) works

PAYG requires no contract or credit check. You purchase a SIM card, top up with credit, and that credit depletes as you make calls, send texts, or use data. When your credit runs out, you simply top up again. There's no monthly bill and no commitment period.

Most PAYG services now offer "bundles" where you can buy monthly allowances (like 5GB data plus unlimited texts and minutes) that expire after 30 days.

SIM only or pay monthly: which offers better value?

When people ask about SIM only or pay monthly, they're usually comparing SIM only deals against pay monthly contracts that include a phone. The answer depends on whether you need a new handset.

The pros and cons of SIM only contracts

SIM only deals offer significant savings if you already own a phone. Without subsidising a handset, your monthly costs drop dramatically..

You also gain flexibility with shorter contract options. Whilst pay monthly phone contracts typically lock you in for 24-36 months, SIM only offers 30-day rolling contracts for maximum flexibility, though 12-24 month contracts provide better rates.

The main disadvantage? You need your own phone, which can mean £200-1000 depending on the model if you don’t have one.

SIM only also requires existing phones to be unlocked. If your previous contract locked your phone to a specific network, you'll need it unlocked before switching to a different provider's SIM.

The pros and cons of pay monthly phone deals

Pay monthly contracts bundling a phone make expensive handsets affordable by spreading costs over 24-36 months rather than paying upfront for a new phone. **This accessibility makes the latest phones available to more people. **

However, you'll pay significantly more overall. The convenience of monthly payments means the total amount paid over your contract exceeds buying the phone outright and getting a cheap SIM only deal. You're also locked into lengthy contracts (typically 24-36 months), and early termination can be expensive.

Monthly costs remain high even after you've essentially "paid off" the phone through your contract. Many people continue these expensive contracts out of habit, not realising they could switch to a SIM only deal and cut their bills in half.

Pay monthly or pay as you go: comparing flexibility and cost

Pay monthly provides better value for regular users, whilst PAYG suits occasional use.

If you use your phone daily for calls, texts, and mobile data, **pay monthly (whether SIM only or with a phone) always works out cheaper. **

PAYG makes sense for genuine light users, perhaps elderly relatives who only make occasional calls, children's first phones where you want to control spending, or backup emergency phones.

If you're checking social media, using maps, streaming music, or browsing websites regularly, you're using gigabytes of data monthly. PAYG becomes prohibitively expensive for this usage pattern.

SIM only vs pay as you go: which is better for data and calling?

For data and calling allowances, SIM only vs pay as you go shows stark differences. SIM only contracts include substantial data allowances (often 10GB to unlimited) and unlimited calling and texting. PAYG provides minimal data and limited calls before credit depletes rapidly.

Key factors to help you choose your next mobile plan

Several personal circumstances should influence your decision between these mobile plan types.

Do you already own a phone?

**If you own a relatively recent smartphone in good working condition, SIM only represents the best value. **

If you need a new phone, consider whether you can afford to buy one outright or nearly-new from a refurbished seller, then pair it with a cheap SIM only deal. This often costs less overall than paying monthly contracts, even accounting for the upfront phone cost.

Only choose to pay monthly with a phone if you specifically need the latest model and cannot afford the upfront cost, or if your credit situation makes getting a SIM only contract difficult.

How much monthly data do you actually use?

Check your current data usage in your phone's settings. Most smartphones track this under "Mobile Data" or "Data Usage" settings. If you're consistently using under 2GB monthly and rarely make calls, PAYG might work, though a cheap SIM only deal would still likely cost less.

Using 5-10GB monthly? You need a proper SIM only contract. PAYG becomes prohibitively expensive at this usage level. Using 20GB+ or frequently running out of data? Unlimited data SIM only plans make sense.

Your credit score and contract length preference

SIM only and pay monthly contracts typically require credit checks. If your credit history has issues, PAYG requires no checks at all, making it accessible to everyone.

Consider your stability, too. 30-day rolling SIM only contracts provide commitment-free flexibility whilst still offering better value than PAYG. More settled and wanting the best rates? 12 or 24-month contracts reduce monthly costs significantly.

Saving money on mobile: when to switch to a SIM only deal

The single best time to switch to a SIM only deal is when your current pay monthly contract ends. Your handset is now yours, fully paid off through your contract, and continuing the same contract means paying for a phone you already own.

**Contact your provider as your contract end date approaches and switch to a SIM only deal with them or a competitor. **

**If you're a Hey!Broadband full fibre customer, you can save even more by bundling our services. **

Conclusion: making the best SIM choice for your budget and lifestyle

Understanding sim-only vs pay as you go options, plus how they compare to pay monthly phone contracts, empowers you to choose wisely. For most people with existing phones and regular usage, SIM only offers the best value by far. PAYG suits only genuine light users who rarely need connectivity. Paying monthly with phones makes sense only when you need a new handset and prefer spreading costs.

At Hey!Broadband, we offer SIM only plans from just £12 monthly for 10GB data (for broadband customers) up to unlimited data plans, all on the UK's fastest 5G network. Ready to save on your mobile bill? Call our friendly UK-based team on 020 4579 0655 to discuss which plan suits your needs, or visit our website to explore our SIM only options and exclusive bundles for broadband customers.