Guest friendly hotels in Bangkok is a label for hotels that do not charge an extra fee for bringing in an unregistered guest into your room to stay overnight. You may have also heard of the label no joiner which means the same thing. Hotels that require their guests to pay an extra fee even though the room had been booked for two is an unfair business practice that occurs through Bangkok hotels. Non guest friendly hotels usually charge a 500 THB ($ 14 USD) fee for bringing in unregistered guests. Some places charge as high as 1000 THB ($ 30 USD).
Fortunately there are many guest hotels in Bangkok. You can find them mainly centered in the popular commercial areas of Sukhumvit Road which is conveniently close to the myriad of nightlife venues and hot spots throughout the area. Here are names of 5 popular guest friendly hotels in Bangkok (as of writing):
1. Ambassador Hotel
2. Citi Chic Boutique Hotel
3. Amari Boulevard Hotel
4. Landmark Bangkok
5. JW Marriott
There are many more guest friendly hotels, with rates ranging from 1000 THB up to 6000 THB ($ 30 USD to $ 170 USD). There are hotels with even lower rates. Some have rates that go as low as 500 THB or $ 14 USD per night, but I highly suggest that you avoid staying in a hotel with such low rates as it will most likely be unclean and far from the center of nightlife activities in Bangkok.
Another alternative is to book your stay in a serviced apartment in Bangkok. Serviced apartments in Bangkok are either run by hotel or private management. They treat their guest with full hotel hospitality such as daily house keeping, use of facilities like a fitness gym and swimming pool. Most up market rooms may be equipped with a full kitchen and washer dryers. Most even provide a free buffet breakfast included in the room rates just like hotels in Bangkok. It would stand to make sense that serviced apartments do not charge a joiner fee because the room's are technically apartments. However you are personally responsible for your guests.
There are many serviced apartments in Bangkok. The most popular one is called Center Point. Currently there are 7 Center Point Hotel properties that are in convenient locations close to main attractions through out Bangkok. They are a fully established serviced apartment, labeled as a hotel, but most of the guest who stay there are vacationers. Personally Center Point hotels are my favorite places to stay in and I never have to worry about having to pay a joiner fee for my guest.