Here’s a short step by step plan how to start working in prostitution in Amsterdam behind the windows.

1. You need to have a valid European passport (EEA), or a valid residence permit.
2. You need to be 21 years or older, in (some) other cities in The Netherlands 18 years or older.
3. You need a residence in The Netherlands.
4. You need to be registered in the Dutch city you live in. This is called a GBA registration. You will need this registration for the next step.
5. You will need to open up a bank account. This is required to do to become a self-employed company, so you need to do this first before going to the next step. A business bank account is not required, and is also often difficult to get as still many banks refuse sex workers. But a personal bank account is enough. Recommended banks are ING and ABN AMRO, since they most often accept sex workers. Rabobank is notorios for refusing sex workers. It's not required to put your earnings on your bank account however.
6. You need to open up your own self-employed company (ZZP) at the Dutch Chambers of Commerce (Kamer van Koophandel). For this you will need your GBA registration and a bank account. You can  register your company under the term prostitution, but better is to register yourself under the term ‘personal services’, to avoid any discrimination from people or companies in the future regarding your job. 
7. Now you need to find a window brothel you can work from. The window brothels are rented out by landlords, or brothel operators as they are called, who have a permit for this. The best way to find one, is to walk into the Red Light District, until you come across one of the many signs brothel operators put up with their phone number. Call the phone number to make an appointment with them for an intake interview. Some window brothel operators also have a website, which are listed below.
8. Take your passport, GBA registration and Chambers of Commerce registration with you for the interview with the brothel operator. During your first meeting with the brothel operator they will do an intake interview with you. The interview is to ensure the brothel operators you’re not being exploited or coerced, and you’re independent enough to do this job.
9. Once the interview is completed, you can start renting rooms from the brothel operator you did the interview with. Prices of the rooms range from 80 to 110 euro during the daytime, and 130 to 200 euro during the night time. You need to pay the room in advance.

Window rental companies:

The Office 52
Oudezijds Achterburgwal 52
1012 DP Amsterdam
www.theoffice52rld.com

My Red Light
Oudezijds Achterburgwal 17
1012 DA Amsterdam
www.myredlight.nl

Carlos Dieke Verhuur (Singel Area)
Spuistraat 15-19
1012 SP Amsterdam
www.carlosdiekeverhuur.com

Tips:
Because prostitution is a legal job in The Netherlands, you need to pay taxes. As a window prostitute you will pay taxes just like every other self-employed person does, which is 21% taxes over your income. Find a good bookkeeper who can help you with this.

Working behind the windows is one of the most independent way of working in prostitution. Because you’re self employed, you decide who you work with, what you do and when you work.

Don’t trust anybody but yourself.

If you need any help or have any questions, there are several organisations who can help you out. These are:

PROUD - Dutch Union for Sexworkers
PROUD is an organisation led by sex workers, offering information and help for sex workers.

(Located in the Red Light District)
Enge Kerksteeg 3
Amsterdam
Phone number: +31628445537
Website: www.wijzijnproud.nl
E-mail: info@wijzijnproud.nl

Prostitution Information Center (PIC)
The PIC is an organisations who informs people about prostitution to anyone that is curious about this.

(Located in the Red Light District)
Enge Kerksteeg 3
Amsterdam
Website: www.pic-amsterdam.com

P&G292
The P&G292 is a government funded organisation aimed to help sex workers.