For journeys governed by UK rules, carry a power bank in your hand luggage, not checked baggage. From 27 March 2026, the UK Civil Aviation Authority’s passenger rules limit travellers to two power banks, require each one to be individually protected when not in use, prohibit recharging a power bank on board, and say it should not be used to charge another device during the flight.
A power bank up to 100 watt-hours normally does not need airline approval. Above 100Wh and up to 160Wh requires approval from the operating airline; over 160Wh is prohibited in passenger baggage. Airlines can impose stricter conditions, so check every operating carrier before departure.
Before you travel:
- Pack no more than two power banks in cabin baggage.
- Check the Wh rating on each physical unit.
- Protect every unit against short circuit and remove it from any gate-checked bag.
- Recheck the operating airline’s current policy.
What changed in the UK rules in March 2026?
The CAA separated power banks from the broader rules for spare batteries because it introduced specific restrictions on their number, charging, use and storage. The current passenger requirements are:
- carry power banks in carry-on baggage;
- bring no more than two per person;
- protect each unit against short circuits when it is not in use;
- do not recharge a power bank on board;
- do not use it to charge another portable electronic device on board;
- follow any stricter airline instruction about where it must be kept.
Suitable protection can include the original retail packaging, a separate protective pouch or another arrangement that prevents the terminals or built-in connectors from contacting metal objects. Keep the unit accessible rather than buried beneath other items.
How do you find the watt-hour rating?
Airline limits use watt-hours, not the charging output printed in watts. A label such as “22.5W fast charging” describes output capability; it does not state battery capacity. Look on the casing or manufacturer specification for a value ending in Wh.
If the casing provides voltage and capacity but no Wh figure, the CAA gives this calculation:
Wh = voltage (V) × amp-hours (Ah)
When capacity is in milliamp-hours: Wh = V × mAh ÷ 1,000.
Use the battery’s labelled nominal voltage, not the USB output voltage or a guessed value. For example, a device labelled 10,000mAh and 3.7V calculates as 37Wh. A 10,000mAh marking without a voltage is not enough to perform that calculation reliably.
Use this capacity decision table
| Labelled capacity | UK baseline | Action before travel |
|---|---|---|
| Up to 100Wh | Allowed without operator approval, subject to the power-bank rules | Check the operating airline, pack in hand luggage and protect the unit. |
| Above 100Wh and up to 160Wh | Operator approval required | Obtain approval before travelling and retain the confirmation. |
| Above 160Wh | Prohibited in passenger baggage | Do not take it as cabin or checked baggage; ask about dangerous-goods transport if necessary. |
| No readable Wh value and insufficient label data | Capacity cannot be verified from the unit | Check the manufacturer documentation and airline before travel; do not rely on a seller title alone. |
Pack it so it remains safe and accessible
- Inspect the power bank for swelling, cracks, heat damage or exposed connectors.
- Confirm the Wh rating and photograph the label in case it becomes difficult to read.
- Place each power bank in its own protective pouch or original packaging.
- Keep it in hand luggage where cabin crew can reach it if needed.
- If your cabin bag is gate-checked, remove the power bank before handing over the bag.
- Follow the crew’s instructions about storage and do not recharge or use the power bank on board.
Check the airline operating each flight
Your booking brand may not operate every leg of a connecting journey. Check the dangerous-goods or battery policy for each operating airline, especially for a unit above 100Wh. Ask the airline if the policy is unclear and keep written approval where it is required.
If you are choosing a unit for future travel, browse Digi4u’s power bank collection, then check three things on the specific product: a readable Wh or complete voltage-and-capacity label, physical size that suits your cabin bag, and charging ports that match your devices. Confirm the same information on the physical unit when it arrives. The airline decision must be based on the actual power bank you carry, not the collection page or seller title.
Common questions before departure
Can a power bank go in checked luggage?
No. Under current CAA guidance it must remain with you in carry-on baggage. Remove it if your cabin bag is transferred to the hold.
Can I charge my phone from it during the flight?
The CAA says power banks should not be used to charge other portable devices on board. Your airline may make that restriction mandatory or add storage rules, so follow the operating carrier and cabin crew.
Is a 10,000mAh power bank automatically allowed?
Not from that number alone. Check the labelled Wh value or calculate it using the labelled nominal voltage. The condition and airline policy also matter.
