1. Understanding What You Are Actually Comparing

Before diving into cost, it helps to be clear about what each option actually is, because the terminology can get muddled.

What is an eSIM?

An eSIM is a digital SIM card built into your phone. Rather than inserting a physical card, you scan a QR code or download a profile, and a new network is activated on your device. Travel eSIM providers sell plans that work across multiple countries by roaming on local networks in each destination. You buy the plan before you leave home, or at any point during your trip, without needing to visit a shop.

What is a local SIM?

A local SIM is a physical SIM card you buy in the country you are visiting, from a local mobile network. You slot it into your phone, top it up or activate a plan, and you are connected to that country’s network directly, often at the same rates locals pay. When you move to a new country, you either buy another SIM or switch back to a travel eSIM.

2. Where Local SIMs Tend to Win on Price

In many parts of the world, local SIMs are genuinely very cheap. In countries where mobile competition is strong and data infrastructure is well developed, you can get large amounts of data for a fraction of what a travel eSIM would cost for the same period.

Regions where local SIMs are typically strong value

•  Southeast Asia (Thailand, Vietnam, Indonesia, Philippines, Malaysia) – data is often very affordable, networks are reliable, and SIMs are easy to buy at airports and convenience stores.
•  South Asia (India, Sri Lanka) – prepaid plans can be extremely cheap, though registration requirements can add complication (see section 6).
•  Latin America (Mexico, Colombia, Brazil, Argentina) – local prepaid SIMs vary by country but are generally good value compared to regional eSIM options.
•  Eastern Europe (Poland, Hungary, Czech Republic, Romania) – local plans are competitively priced and coverage is generally strong.

In these regions, a local SIM for a month of data can cost a fraction of an equivalent travel eSIM plan. If you are staying in one country for several weeks, the savings can be meaningful, particularly if you are buying for multiple family members.

3. Where eSIMs Tend to Win on Value

Price per gigabyte is not the only measure of value. In some situations, eSIMs offer a better overall deal when you account for the full picture.

Situations where eSIMs often make more practical and financial sense

• You are moving between multiple countries in a short space of time and a single regional eSIM covers them all without buying a new SIM in each place.
• Local SIM registration requirements are complex, time-consuming, or require documentation your family does not have readily to hand.
• You are in a country where the cost of local SIMs is not significantly lower than a travel eSIM, such as parts of Western Europe or North America.
• The convenience of setting up data before arrival removes the stress of landing in a new country without connectivity, particularly useful with children in tow.
• Your UK phone number matters, for example for banking apps, two-factor authentication, or keeping in touch with school or family, and you need to manage both a UK number and local data.

4. The Real Costs You Need to Factor In

A straightforward price comparison between an eSIM plan and a local SIM plan often misses several costs that matter in practice. Here is what to include in your real-world calculation.

Costs often overlooked with local SIMs

• The SIM card itself (sometimes free, sometimes a small fee).
• Transport to and from a shop or airport kiosk on arrival, particularly if you land late or in a remote area.
• Time spent finding, queuing, and setting up the SIM, which has a real cost when you are travelling with children.
• Leftover credit on a SIM you cannot use once you leave the country.
• Replacement costs if a physical SIM is lost or damaged.
• Multiple SIMs across multiple family members multiplies all of the above.

Costs often overlooked with eSIMs

• Premium pricing compared to local rates, particularly for longer stays in one country.
• Throttled speeds on cheaper unlimited plans that may push you towards a more expensive option (see our article on unlimited eSIM plans).
• Purchasing separate eSIMs for each family member’s device if hotspot sharing is restricted.
• Some providers charge for top-ups or extensions rather than offering rolling plans.

5. How Family Size Changes the Calculation

Most cost comparisons you will find online are written with solo travellers in mind. For families, the maths shifts considerably.

Travelling with one or two shared devices

If your family can share data through one device acting as a hotspot, you are essentially only paying for one plan regardless of whether you choose eSIM or local SIM. In this case, cost per gigabyte becomes the main deciding factor, and local SIMs often have the edge in data-cheap regions.

Travelling with multiple devices needing independent data

If your children have their own tablets or phones that need direct data access, or if a parent works remotely and needs a dedicated connection, you are potentially buying multiple plans. At this point, the convenience of managing one eSIM provider for all devices, versus queuing at a local shop for a SIM for each person, becomes a more significant factor in the total cost calculation, not just the data price.

Children’s devices

A child’s tablet used primarily for offline downloads, games, and occasional streaming does not need its own SIM at all if it can connect via a parent’s hotspot. Thinking carefully about which devices actually need independent connectivity can reduce your costs significantly under either model.

6. Practical Challenges of Local SIMs

Local SIMs are not always as simple as walking into a shop and walking out connected. Being aware of the common obstacles in advance helps you plan around them.

Registration requirements

Many countries now require SIM registration with a local ID or passport. In some cases this is a quick scan of your passport at the point of purchase. In others, the process is more involved or the SIM takes time to activate. Check the requirements for each country on your itinerary before you arrive.

Language barriers

In some destinations, navigating local mobile network shops without speaking the language can be difficult. Staff may not speak English, plan details may not be available in English, and understanding what you are buying can be hit and miss. This is a minor inconvenience for solo travellers but can be genuinely stressful with children waiting.

Finding a reliable seller

Airport kiosks are convenient but are sometimes significantly more expensive than in-city shops. Third-party sellers are not always reliable. The safest approach is to buy directly from a major local network’s own shop or official airport desk, though this is not always possible on arrival.

Staying long enough to make it worthwhile

If you are only in a country for a few days, the time and effort of getting a local SIM may not be worth the saving over an eSIM. Local SIMs tend to represent better value the longer you stay. Check out our ‘which is better’ guide here.

7. Practical Challenges of eSIMs

eSIMs are not without their own complications, and it is worth knowing what these are before assuming they are the easy option.

Device compatibility

Not all phones support eSIM. Older devices, budget Android phones, and some phones sold in certain markets may not have eSIM capability. If your child uses an older tablet or a mid-range Android device, it may not be compatible. Check each device individually before relying on eSIM as your family’s main connectivity solution.

Network lock

Some phones, particularly those bought on UK contracts, may be locked to their original network’s eSIM profile and unable to add a third-party travel eSIM without being unlocked first. Contact your home network well in advance of travel to resolve this if needed.

Coverage gaps

Travel eSIMs roam on local networks, but they do not always have agreements with the best local network in every country. In some destinations, a travel eSIM may give you access to a secondary network with patchy coverage, while a local SIM from the dominant network would give you much stronger signal in the same location.

Customer support

If an eSIM stops working mid-trip, you are relying on online or app-based support from a provider who may be in a different time zone. With a local SIM, you can walk back to the shop. Neither is guaranteed to be quick, but local support can sometimes be faster to resolve practical issues.

8. A Side-by-Side Comparison

Factor	eSIM	Local SIM
Setup convenience	Buy before you leave, activate on arrival or in advance	Requires finding a shop on arrival in each country
Price per GB	Often higher, especially for longer stays	Often cheaper, particularly in Asia and Latin America
Multi-country trips	Regional plans can cover many countries in one purchase	New SIM needed for each country unless using a global SIM
Device requirement	Requires eSIM-compatible, unlocked device	Requires unlocked device with physical SIM slot
Registration	Usually just an email and payment	May require passport and local registration process
Network quality	Depends on roaming partner in each country	Can choose the best local network directly
Keeping UK number	Can run alongside UK eSIM on dual-SIM devices	Physical SIM replaces UK SIM unless device has two slots
Hotspot sharing	Often restricted or capped on travel eSIM plans	Typically included on local prepaid plans
Leftover credit	Unused data stays within plan validity period	Leftover credit lost when you leave the country
Suitable for families	Easier to manage across multiple devices	More admin per device, but can be significantly cheaper

9. Which Should Your Family Choose?

There is no single right answer, but here are some practical rules of thumb based on common family travel scenarios.

Consider eSIM if you are:

• Moving through multiple countries in a month or less and do not want the hassle of a new SIM in each place.
• Travelling with young children where minimising admin on arrival is a genuine priority.
• Visiting countries where local SIM registration is complex or documentation requirements are unclear.
• Primarily in Western Europe or North America where local SIM prices are not dramatically cheaper.
• Relying on your UK number for banking or two-factor authentication and need to keep it active.

Consider local SIM if you are:

• Spending several weeks or more in a single country, particularly in Southeast Asia or Latin America.
• Travelling with older children or teenagers who each need their own data and the per-GB cost saving matters.
• Comfortable navigating local shops and have researched the best local networks for your destination in advance.
• On a tighter budget where even modest per-GB savings across a family add up to a meaningful amount over several months.

Consider a hybrid approach if you are:

• On a long trip covering very different regions. Use an eSIM for multi-country legs and switch to local SIMs for longer stays in one place.
• Travelling as a family where one parent works remotely and needs a reliable dedicated connection, while the children share a hotspot from a second device on a local SIM.

10. Before You Decide: Checklist

Ultimately, the cheapest option for your family depends on your specific itinerary, the devices you are travelling with, and how much weight you give to convenience versus cost savings. For many long-term travelling families, the answer ends up being a combination of both: eSIM for the busy multi-country legs and local SIMs for the longer stays in one place.

If you are just starting to plan your data strategy for a long trip, the checklist above is a good place to anchor your thinking before you start comparing specific plans and prices.