There are obviously a few routes you can take to go between these two countries Laos and Cambodia. I was staying in Don Det down near the Cambodia border so I did the Nong Nok Khieng to Trapeang Kreal crossing. This is also a money saving tip by the way as you want to cross your borders and get your visas in the cheapest way possible. For this basis of this post and all my world borders, I’m talking about using a British or Irish passport as those are the two I travel on. I happen to know that Russians and Luxembourg passports don’t need visas for Laos and that other nationalities will pay different amounts for their Cambodian Visa. 
There are lots of buses available to book in Don Det and Don Khong. Shop around and book your bus!
What is needed going from Laos to Cambodia?
– A valid passport
– A passport photo (carry two just in case, I always carry them)
– In US Dollars You’ll need $27
– All the forms filled in
Sorting out your Cambodian Visa:
OK please listen to me here and do it yourself. Don’t pay $30 or more to a bus driver or the company to do it for you. Yes they will get you across the border no problem and with the valid visa, but you’re paying them money that you can save. Remember Cambodia and Laos are cheap and you can get a hostel, a beer and a meal any evening for $5 dollars, so keep the money for yourself. Tell them you are doing it yourself. You will get all your Laos and Cambodia visa forms at Ban Nakasang – fill them in while you wait for the bus.
Do you have to pay to leave Laos at Nong Nok Khieng?
It’s supposed to be free and normally it will be especially if you are Lao or Cambodian. For tourists they try to charge you $2 US dollars at weekends for overtime. I ended up having to pay it after an hour of arguing and you might have to too.
At weekends particularly they try to charge an overtime fee which is outrageous and costs $2 US so for advice don’t cross the border at the weekend.
Crossing the border itself from Laos to Cambodia:
It’s a very short walk from the Laos border point across the road and bridge into Cambodia – an easy walk to do and suddenly all you need to do is get your visa. Pay them $25 at the booth, get the visa and on you go into the Kingdom of Cambodia!
You are now in a place known as Trapeang Kreal.
Just so you are aware this is not really a village at all – it’s just the border crossing but ultimately you board your bus there and head onwards, south through Cambodia. I don’t know if this is unusual but our bus waited for about two hours there at the border so we were sitting around for two hours. I quite enjoyed this as my Irish travel buddies (who got the bus with me but sorted their visas through the bus driver) were waiting for me there! So with two Irish guys and an Irish girl sitting on the border having just entered Cambodia (I was on country number 68), it was time for a beer!!
After arriving in Cambodia at Trapaing Kreal you may have to wait for a few hours for your onward bus so just relax. Time to admire your visa, read your guidebook and have a beer and some local food before your onward journey. The bus down south to Phnom Penh could take up to 12 hours but you’ll love it.
How much did it cost to get from Laos to Cambodia?
The grand total was $27 US, which was $2 US to leave Laos and $25 for the Visa for Cambodia. The cheapest you can really get this for is $25 US.
For more articles like How to get from Laos to Cambodiavisit Jonny Blair’s fantastic travel site Don’t Stop Living, one of the Best travel blogs on the internet with perpetual travel tips.. Check here for free reprint license: Border from Laos to Cambodia.