Best 21-day eSIM Plans for United Kingdom

Q: What eSIM do I need for 21 days in United Kingdom?

For a 21-day trip to United Kingdom, look for a plan with at least 21 days of validity. Plans start from $2.34. Pro members save 7%, Premium members save 12%.

Q: How much data do I need for 21 days in United Kingdom?

For 21 days, a typical traveler uses 1–2 GB per day for maps, messaging, and social media. That is roughly 21–42 GB for your trip.

Q: Can I extend my eSIM if my 21-day trip runs long?

Purchase an additional plan from LTE.app at any time. No need to find a SIM card shop — data purchases are available 24/7.

Going to United Kingdom for 21 days (3 weeks)? These plans cover your full trip — all with instant QR delivery, no contract, and no SIM card to pick up at the airport.

Starting from (Free)

$2.34

Pro membership — save 7%

$2.18

Premium membership — save 12%

$2.06

Get Pro or Premium →

Recommended 21-day plans — United Kingdom

Best Value

Uki Mobile

999 GB

30 days validity

$72.00

$0.07/GB

All 13 plans covering 21+ days

Uki Mobile

999 GB

30 days validity

$72.00

$0.07/GB

Uki Mobile+

50 GB

30 days validity

$54.00

$1.08/GB

Uki Mobile

20 GB

30 days validity

$31.00

$1.55/GB

Uki Mobile

10 GB

30 days validity

$19.00

$1.90/GB

Uki Mobile+

20 GB

30 days validity

$38.50

$1.93/GB

Uki Mobile+

10 GB

30 days validity

$23.50

$2.35/GB

Uki Mobile

5 GB

30 days validity

$13.00

$2.60/GB

Uki Mobile

3 GB

30 days validity

$9.00

$3.00/GB

Uki Mobile+

5 GB

30 days validity

$15.50

$3.10/GB

EUconnect

3 GB

30 days validity

$9.50

$3.17/GB

Oceanlink

3 GB

30 days validity

$10.50

$3.50/GB

Eurolink

3 GB

30 days validity

$11.00

$3.67/GB

View all United Kingdom plans →

Other trip lengths for United Kingdom

3-day United Kingdom eSIM 5-day United Kingdom eSIM 7-day United Kingdom eSIM 10-day United Kingdom eSIM 14-day United Kingdom eSIM 30-day United Kingdom eSIM

21-day eSIM plans by destination

21-day Japan 21-day Thailand 21-day France 21-day Italy 21-day Germany 21-day UAE 21-day Spain 21-day Greece 21-day Indonesia 21-day Vietnam 21-day Australia 21-day Taiwan

Frequently asked questions — 21-day United Kingdom eSIM

What eSIM do I need for 21 days in United Kingdom?

Look for a plan with at least 21 days of validity. The plans above all cover your full trip. Activate when you land — validity starts from first use, not from purchase.

How much data do I need for 21 days in United Kingdom?

A typical traveler uses 1–2 GB per day for maps, messaging, and occasional video. For 21 days that is roughly 21–42 GB.

When should I install my United Kingdom eSIM?

Install before you travel, at home over Wi-Fi. Activation begins when you arrive and connect to a local carrier.

Can I top up if I run out of data?

Many plans are rechargeable. You can purchase an additional plan from LTE.app at any time — no need to find a SIM card shop.

Save on every trip with Pro or Premium

Pro 7% off · Premium 12% off · Smart Coach AI · Offline activation

Download LTE.app →