Driving Abroad with Type 1 Diabetes: Licenses, Rental Cars, and Low Blood Sugar Rules (2026)

Thanksgiving is 19 days away, November is Diabetes Awareness Month, and the holiday trips are the ones where a rental car makes the difference: driving to the family house outside London, up the Amalfi Coast, or across the South Island with the people you came to see. Renting a car abroad with type 1 diabetes (T1D) means two sets of rules, and they sit in different places. One set is paperwork: whether your US license works where you are going, whether you need an International Driving Permit (IDP), and what the rental counter will ask for. The other set is medical: the low blood sugar numbers that change when you cross a border, because the United Kingdom writes its driving rules down in a way the United States does not. This guide covers both, in that order, and it ends with the insulin and packing rules for a car that sits in the sun.

One honest note about who is writing this. I have had type 1 diabetes for 20 years and I drive with an Omnipod 5 insulin pump and a Dexcom G7, a continuous glucose monitor (CGM) that reads glucose every few minutes. I pre-bolus in my usual way before eating, and I treat lows with sugar packets. This guide does not invent a story about me driving in another country, and it does not tell you what medicine to take or what amount to use. Those decisions belong to you and your care team, and section 7 lists exactly what to ask them before the trip.

This guide is the driving-abroad companion to the rest of the site, and it does not repeat them. The road-trip guide covers driving with type 1 diabetes inside the United States: the US driving routine, snacks in the car, and long drives at home. The international travel guide covers the whole trip abroad: the doctor's letter, customs, finding insulin, and crossing time zones. The insulin customs guide covers what to declare at the border, and the TSA rules guide covers the flight out. Read the international travel guide before you book anything, read the road-trip guide for the driving habits, and keep this guide for the rental car.

1. Your US license abroad: the short version

There is no single answer to whether your US license works abroad, because each country writes its own rule. The U.S. Department of State puts it plainly on its driving abroad page: "Some countries accept a U.S. driver's license. In many others, you must have an International Driving Permit (IDP)." The same page tells you where to find your answer: "Review the local traffic laws, drivers license requirements, and road safety tips in the Travel and Transportation section of the destination Travel Guidance page." That is the step to take before you book the car, for every country on the trip, because the answer changes at each border.

• Canada and Mexico: your US license is enough. Both countries accept a US driver's license for visitors on short trips, and neither requires an IDP. You still need a passport or another approved travel document to enter either country, whether or not you are driving.
• The United Kingdom: your US license works for 12 months. GOV.UK says a visitor can drive any type of small vehicle listed on a full and valid licence for 12 months from when they last entered Great Britain. After 12 months you need a UK licence. For a holiday trip, the 12 months covers you.
• Everywhere else: check the country page, and assume nothing. The State Department's country pages are the source to trust, not a travel blog and not the rental company's marketing page. Look for the Travel and Transportation section, read the driver's license line, and write down what it says. If the page says an IDP is required, get one before you leave, because the next section explains why you cannot get one after you land.
• You are subject to local traffic laws while you drive abroad. That is the State Department's wording, and it is the whole point of this guide: the speed limits, the side of the road, the alcohol limits, and the diabetes driving rules are the destination's, not yours. The United States has no say in what a police officer in Italy or the UK asks to see.

2. The International Driving Permit: what it is and how to get one

An International Driving Permit, or IDP, is a booklet that translates your US driver's license into 10 languages so that police and rental desks abroad can read it. It is not a license. It does not replace your US license, and it is worthless without it. AAA puts it this way: "An International Driving Permit works in tandem with your U.S. driver's license and does not replace it. You still need to carry your U.S. driver's license at all times while driving abroad." Carry both, every time you drive.

• Only two organizations can issue one in the United States. The U.S. Department of State has authorized exactly two: the American Automobile Association (AAA) and the American Automobile Touring Alliance (AATA). Any other website that offers an IDP is a scam. Do not buy one from a site that is not AAA or AATA, however official it looks.
• What you need, and what it costs. AAA asks for a completed application, two original passport photos, your current US driver's license, and a $20 fee, plus any sales tax or shipping. You can apply at a local AAA branch, by mail, or online through AATA.
• Apply before you leave, and not too early. The document is only issued in the United States, so you cannot get one after you land. AAA says you must apply within six months of your desired effective date, and once issued, an IDP is valid for one year. USAGov adds that an IDP cannot be renewed, so if yours has expired, you apply for a new one.
• Where it is valid. AAA says the IDP is valid in more than 150 countries. That does not mean every country requires it. AAA lists Austria, Bulgaria, Czech Republic, Greece, India, Italy, Japan, Poland, and Spain among the countries that require an IDP, and says France and Hungary require either an official translation of your license or an IDP. Japan is the strictest case in the list: Japanese law requires the officially issued permit.
• When in doubt, bring one. The IDP costs $20 and fits in a glove box. A refused rental car costs a holiday. If your trip touches more than one country, the IDP covers you in the strict one even if the easy one would not have asked for it.

3. Renting the car: what the counter asks for

Rental companies write their own terms on top of the law, and the terms are what the person at the counter follows. Read the rental terms for the exact location before you book, because the same company can ask for different documents in different countries. What follows is what the big companies actually print.

• Your license, your IDP, and your passport, together. Hertz's rental terms in several countries require an IDP from all non-European Union renters, and say the IDP "translates the national licence into various languages and is on its own, without the national licence, not acceptable." In some Hertz locations the terms call the IDP a local legal requirement, and staff will ask to see one before renting the vehicle. Avis's rental FAQ says the same thing from the other side: "If you're driving abroad, you and your additional driver will also need to bring your International Driving Permits." Bring all three documents to the counter, and keep them together in the car while you drive.
• A license you have held for at least one year. Hertz requires a valid national driver's license held for at least one year. Avis requires the same for hiring in the UK: a full, valid licence held for at least one year. A licence held for less than a year will not rent a car abroad.
• Age rules and the under-25 fee. Minimum rental ages vary by country and by company, and drivers under 25 pay an extra daily fee and are limited to smaller car groups. Avis says drivers under 25 pay an extra fee per day. If the main driver is under 25, check the age rule for the exact location before booking, and budget for the fee.
• Insurance: your US policy may not follow you. The State Department says: "Your U.S. auto insurance may not cover you when driving in other countries. Check with your insurance company before you go." The same page adds that even if your insurance is accepted in another country, the coverage may not meet local requirements, and that you should carefully review the insurance offered by the rental company. Ask your insurer what your policy covers abroad, read what the rental includes before you sign, and keep the emergency number for the rental company and your insurer in your phone.
• Ask before driving into another country. Rental agreements often limit which countries the car may enter, and some require advance permission. Tell the rental desk every country on your route when you pick the car up, and get the answer in writing on the agreement.

4. The low blood sugar rules change at the border

This is the section that makes this guide different from a general driving-abroad guide. Low blood sugar, or hypoglycaemia, slows reaction time, clouds judgment, and can make driving erratic, and every country that writes driving rules for diabetes writes them around that fact. The United States and the United Kingdom agree on the number and disagree on how strictly it is written down, and knowing both versions keeps you safe on either side of the Atlantic.

The US practice. The American Diabetes Association (ADA) recommends a starting glucose above 90 mg/dL before driving. Regular glucose checks are recommended on trips over one hour, and if low blood sugar happens while driving, the driver should pull over, treat the low, and not drive again until glucose has returned to normal range for more than 30 minutes. Those are recommendations, not law. The habit to build at home is the same one to use abroad: check before you start the car, keep fast-acting sugar in the car, and never drive through a low to save time.

The UK rules. The United Kingdom writes the numbers down, and the DVLA leaflet INF294, "A guide to insulin treated diabetes and driving," is the source. DVLA is the Driver and Vehicle Licensing Agency, the UK body that issues driving licences. The leaflet's rules for car and motorbike drivers treated with insulin are:

• Do not drive if your glucose is 4.0 mmol/L or below. That is 72 mg/dL. The leaflet says: "Don't drive if your glucose (sugar) level is 4.0 mmol/L or below." Below 4.0 mmol/L, reaction time slows and judgment is affected.
• If it is between 4.0 and 5.0 mmol/L, eat first. The leaflet says to eat a fast-acting carbohydrate snack, for example a sugary drink, and then drive. In this site's own routine that snack is sugar packets: one packet at 60 to 70, two packets below 60, then check again.
• Check before driving and at least every 2 hours. The leaflet requires checking glucose just before you start driving and continuing to check at least every 2 hours during the drive, with no more than 2 hours between checks at any time. If you use a continuous glucose monitor (CGM), use a medically approved device, keep a finger-prick monitor as backup, and confirm with a finger prick if the CGM reading does not match how you feel.
• After a low, wait 45 minutes. The leaflet says to wait at least 45 minutes after glucose levels return to at least 5.0 mmol/L, which is 90 mg/dL, before driving again, because that is how long it takes for brain function and reaction time to fully recover. The 45 minutes starts when the number is back above 5.0, not when you finish the snack.
• Tell the DVLA if you hold a UK licence. Anyone whose insulin treatment lasts, or will last, over three months must tell the DVLA, using form DIAB1. The GOV.UK diabetes and driving page says you can be fined up to 1,000 pounds if you do not tell the DVLA about a medical condition that affects your driving. Once notified, the DVLA issues insulin-treated drivers a licence renewed every one, two or three years. That renewal rule is for UK licence holders, not for visitors: as a visitor driving on a US licence, you do not report to the DVLA, but the driving numbers above still describe safe practice on UK roads.

The same number, two different weights. Note that 5.0 mmol/L is 90 mg/dL, so the UK's safe-to-drive floor and the ADA's recommended starting glucose are the same number. The difference is what backs it: in the US it is a clinical recommendation, in the UK it is written guidance from the licensing authority, with a fine behind the duty to report. Treat the UK numbers as the rule on UK roads, the US numbers as the habit at home, and the stricter of the two wherever you are unsure.

Other countries write their own rules, or none at all. This guide does not list them, because the list would be out of date the moment it was printed. Check the driving rules for your destination the same way you checked the license rules: on the State Department country page, and on the destination government's own driving pages.

5. Your CGM and pump in a rental car abroad

A rental car abroad is the worst place for a device problem: an unfamiliar car, an unfamiliar road, and no backup plan within reach. The habits below are the same ones from the road-trip guide, tightened for a car you do not own and roads you do not know.

• Set your low alert above your driving floor, and keep it loud. Your driving floor is 90 mg/dL, so a low alert set at 90 or above gives you warning before you reach it. The Dexcom G7 gives a 20-minute warning when your glucose is heading toward 55 mg/dL, through its Urgent Low Soon alert, and its Urgent Low alert at 55 mg/dL cannot be turned off or silenced. Use those alerts as your safety net, not as your plan: the plan is the check before you start the car and the checks every two hours after that.
• Keep a finger-prick meter in the car. The DVLA leaflet says to carry a finger-prick monitor as backup and to use it to confirm your glucose if your CGM device or sensor is not working, or if the CGM reading does not match how you feel. Sensors fail, phones die, and Bluetooth drops. The meter is the backup that does not need a signal.
• Keep the phone and receiver charged, and keep the app running. A dead phone is a dead CGM display. Charge the phone and receiver every night, carry a car charger and a cable that fits the rental car's ports, and do not close the CGM app while you drive. If the rental car has wireless charging, test it on the first drive, not on the third.
• Pull over before you test or treat. The DVLA leaflet says to pull over safely before testing or checking, and to switch the engine off and remove the keys from the ignition while you treat a low. Testing while driving is distracted driving, and the leaflet is blunt about it: you must stay in full control of your vehicle at all times, and the police can stop you if they think you are not in control.
• Learn the road before the first drive. A rental car in the UK, Ireland, Australia, or Japan puts the driver on the other side of both the road and the car. Take the first drive in daylight, on a quiet road, before the trip that matters. Roundabouts, one-way systems, and motorway slip roads are easier to learn at 20 miles an hour than at 60.

6. Insulin in a hot rental car

A rental car in the sun is the fastest way to ruin insulin on a trip, because the car heats up far faster than the air outside it. The rule is simple and absolute: never leave insulin in a parked car. The numbers behind it come from the insulin label and from the National Highway Traffic Safety Administration (NHTSA), the US road safety agency.

• The label limits. The NovoLog prescribing information says unopened insulin belongs in a refrigerator at 36 to 46 degrees Fahrenheit (2 to 8 degrees Celsius) until its expiration date, and that in-use insulin stays below 86 degrees Fahrenheit (30 degrees Celsius) for up to 28 days. It also says do not freeze insulin and do not expose it to excessive heat or light. For pump users, the same label says do not expose insulin in the pump reservoir to temperatures above 98.6 degrees Fahrenheit (37 degrees Celsius). Your own insulin may have different limits, so read your own label: the numbers above are NovoLog's, and they are the example, not the rule for every insulin.
• How fast a parked car breaks those limits. The NHTSA says the temperature inside a parked car can rise about 20 degrees in 10 minutes, and can reach 110 degrees even when it is only in the 60s outside. That means a car parked in the sun on a mild day passes the 86-degree limit for in-use insulin in minutes, and a car parked on a hot day passes it before you finish lunch.
• Take the bag with you, every stop. Insulin rides in the bag you carry, not in the trunk, the glove box, or the door pocket. When you stop for a meal, a viewpoint, or a shop, the diabetes bag comes with you. On hot days, keep the insulin in a cooler or a FRIO bag, and keep spare insulin in the hotel fridge, not in the car. The hotel insulin storage guide covers the fridge, the ice bucket, and what to do when the room has no fridge at all.
• Heat and cold both matter, in different seasons. Summer ruins insulin with heat, and winter ruins it with freezing: the same label that says do not expose insulin to excessive heat also says do not freeze it and do not use it if it has been frozen. A car parked overnight in freezing weather is as dangerous to insulin as a car parked in the sun. The insulin cooling guide covers both directions, with the cooling methods that work on flights, road trips, and beach days.

7. The pre-trip checklist and the care-team conversation

Book the care-team conversation before the trip, not from a hotel room after a problem. Ask your care team whether driving abroad is safe for you, what to do if you have a severe low while driving, and who to call in the country you are visiting. Then pack for the drive the same way this site packs for every trip: with the 20% extra buffer, counted before you leave.

• Paperwork: US driver's license, International Driving Permit, passport, rental agreement, insurance documents and emergency numbers, and a travel letter from your care team listing your insulin, pump, and CGM.
• Driving kit in the car: sugar packets for lows, one packet at 60 to 70, two packets below 60, then check again; a blood glucose meter and strips; spare CGM sensors and pump supplies; a phone charger and cable that fits the rental car; a small flashlight for night checks.
• Insulin and supplies: insulin for the whole trip plus 20% extra, split between two bags so one lost bag does not end the trip; a cooler or FRIO bag for hot days; spare pens or vials in the hotel fridge. If supplies are lost or stolen abroad, the lost and stolen recovery guide covers the replacement steps, and the finding insulin abroad guide covers buying insulin in another country.
• Before the first drive: check your glucose, set your low alert above 90 mg/dL, confirm the phone and receiver are charged, learn which side of the road you are on, and set the mirrors and seat before you move. A rental car you have never driven deserves a slow first mile.
• Questions for your care team: Is driving abroad safe for me on this trip? What should I do if I have a severe low while driving in another country? Do my driving rules change if I am the only driver, or if the drive is long? What do I do if my CGM or pump fails abroad and I cannot get a replacement quickly?

If the paperwork feels like too much, drive less and walk more. A rental car is a convenience, not a requirement. Trains, buses, and a local driver cover most holiday trips, and they remove the license question, the rental question, and the driving numbers all at once. The car is worth it when the trip needs one: a coast road, a village with no bus, a family house outside town. When the trip does not need one, the simplest driving plan is no driving at all.

Frequently Asked Questions

Q: Do I need an International Driving Permit to drive abroad with a US license?

A: It depends on the country. The U.S. Department of State says some countries accept a US driver's license, and in many others you must have an International Driving Permit (IDP). Canada and Mexico accept a US license with no IDP. AAA lists Austria, Bulgaria, Czech Republic, Greece, India, Italy, Japan, Poland, and Spain among the countries that require one, and says France and Hungary require either an official translation of your license or an IDP. Check the Travel and Transportation section of the State Department's country page for your destination before you book the car, and bring the IDP even when you think you will not need it: a rental desk can ask for it at the counter, and some countries require it by law.

Q: Where do I get an International Driving Permit, and what does it cost?

A: Only two organizations are authorized by the U.S. Department of State to issue IDPs in the United States: the American Automobile Association (AAA) and the American Automobile Touring Alliance (AATA). Any other website that offers one is a scam. You apply at a AAA branch, by mail, or online through AATA. You need a completed application, two original passport photos, your current US driver's license, and a $20 fee, plus any sales tax or shipping. Apply before you leave: the document is only issued in the United States, and you must apply within six months of your desired effective date. Once issued, an IDP is valid for one year and cannot be renewed.

Q: Can I rent a car abroad with just my US license?

A: Sometimes, but do not count on it. Hertz's rental terms in several countries require an IDP from all non-European Union renters, and say the IDP on its own, without the national licence, is not acceptable. Avis's rental FAQ says that if you are driving abroad, you and your additional driver will also need to bring your International Driving Permits. Hertz also requires a valid national driver's license held for at least one year, and Avis requires a licence held for at least one year with an extra daily fee for drivers under 25. Bring your US license, your IDP, and your passport to the counter together, and read the location's own rental terms before you book.

Q: What blood sugar level is safe for driving abroad?

A: The number is the same on both sides of the Atlantic, but the rules around it are not. In the United States, the American Diabetes Association recommends a starting glucose above 90 mg/dL before driving, regular checks on trips over one hour, and pulling over if you go low, then waiting until your glucose is back in normal range for more than 30 minutes before driving again. In the United Kingdom, the DVLA leaflet says do not drive if your glucose is 4.0 mmol/L (72 mg/dL) or below, eat a fast-acting carbohydrate snack if it is between 4.0 and 5.0 mmol/L, check before driving and at least every 2 hours on a long drive, and wait at least 45 minutes after your glucose returns to at least 5.0 mmol/L (90 mg/dL) before driving again. Treat the UK numbers as the rule on UK roads, and the US numbers as the habit at home.

Q: Do I need to tell the DVLA about my diabetes if I am visiting the UK?

A: No. The duty to tell the DVLA, the Driver and Vehicle Licensing Agency, sits with people who hold or apply for a UK licence: anyone whose insulin treatment lasts, or will last, over three months must tell the DVLA, and insulin-treated UK licences are then renewed every one, two or three years. As a visitor you drive on your full and valid US licence for up to 12 months from when you last entered Great Britain, and the GOV.UK page for visitors lists no DVLA notification step. What does apply to you on UK roads is the driving practice in the DVLA leaflet: check before driving and every two hours, do not drive at or below 4.0 mmol/L, and wait 45 minutes after a low before driving again.

Q: What do I do with my insulin in a hot rental car?

A: Take it with you when you leave the car. The NovoLog label says unopened insulin belongs in a refrigerator at 36 to 46 degrees Fahrenheit (2 to 8 degrees Celsius), in-use insulin stays below 86 degrees Fahrenheit (30 degrees Celsius) for up to 28 days, and insulin must never be frozen or exposed to excessive heat. A parked car breaks that limit fast: the National Highway Traffic Safety Administration says the inside of a car can rise about 20 degrees in 10 minutes, and can reach 110 degrees even when it is only in the 60s outside. Keep your insulin in a bag you carry, not in the trunk or glove box, use a cooler or FRIO bag on hot days, and keep the pump reservoir out of direct sun as well: the label says do not expose it to temperatures above 98.6 degrees Fahrenheit (37 degrees Celsius).

Additional Details

• Name: Driving Abroad with Type 1 Diabetes: Licenses, Rental Cars, and Low Blood Sugar Rules (2026)
• Description: Renting a car abroad with type 1 diabetes means two sets of rules: the license and rental paperwork, and the low blood sugar numbers that change at the border. The 2026 guide: the IDP from AAA, what the rental counter asks for, the UK DVLA numbers, and keeping insulin safe in a hot rental car.
• Published: 2026-11-07