Cross Border rental car driving from Croatia

We rented in Split, went to Bosnia and back to Split, we had to make sure to a Sticker on the vehicle and show the paperwork for the car and the rental, pay a small fee at the boarder, so simple J

Just let the rental company know where you are going. Last september they charged us $90 extra to drive to italy. We did return the car in Croatia.

In May 2024, before we left the states, we arranged for a car rental through Enterprise that we picked up in Split. We paid a fee for going into other countries and an extra fee for dropping off at a different location. All went smoothly. We drove to Mostar, Bosnia (a few hours' drive, stopping at Bravica Falls along the way). It was easy, peasy. I believe that we had to pay one toll (two booths: one to collect toll ticket, one to pay toll ticket when done) and stopped at two border crossing booths (one when leaving Croatia, one when entering Bosnia, about 1/2 mile apart). The roads were great. When we drove from Mostar to Kotor, Montenegro, the two lane, lined, curbed highway sometimes went down to a single unlined paved lane and then back again to look more like a highway so just make sure that you're on the correct path even though it may not look like it. We returned the car to Dubrovnik before flying out.

As always this forum is so helpful--grateful to the group knowledge! I'm jumping on this thread with similar but not identical questions. We (husband & I) are heading to Croatia & Slovenia etc in September. We've rented cars for various legs. My questions:
1-We are renting a car for the day in Dubrovnik in order to visit Mostar in Bosnia--the RS guide & some threads here talk about a "green card" from the rental agency to use as proof of insurance for crossing from Croatia into Bosnia (unless I've misunderstood). Where do we get such a "green card" and is it at the border that it needs to be shown (we do have car insurance, through our credit card agency)
2-Will also have a rented car for a few days separately in Slovenia to explore the Julian Alps. Again, various sources mention e-vignettes required to pay tolls. Do we buy/get these at the car rental agency in Ljubjana or is there some other process needed?
Thanks for any advice.

Kris - you will need to purchase the green card from the rental company and confirm that the rental company allows you to take the car into those countries. I read lots of threads about Nova Car as being the best bet in Croatia so went with them last summer and had no issues.

Evelyn - my experience last summer renting in Croatia with Nova Car was that I paid for the green card when I booked the rental, and they gave it to us with the paperwork when we picked up the car. At the Bosnian border, they only asked for passports. Even though no one ever asked for the green card, you still absolutely need it; otherwise you are not authorized to take the car out of the country and you are not following the rules of the rental agreement. Not having it could result in a lot of trouble if you get in an accident, etc. In Slovenia, buy the vignette online when you pick up the rental - you need the license plate number, so you can’t purchase ahead of time. I believe as of last year vignettes were all electronic.

Muguet: Thanks for this clear helpful info on car rental in this region. I will dig into the green card purchase with our rental company asap! Happy travels to all.