You just can't miss them. Regardless the brand and type of the car, they all are bright yellow and they will take you wherever you need to go.
There are about 14.000 taxis in Athens. Average every taxi is operational 19 hours per day driving 350 km. Every day taxis in Athens drive about 5 million kilometers totaling up to 1.8 billion kilometers a year.
Taxis in Athens are cheap which accounts for the high number of kilometers yearly.
One could say the Athens taxis have their own set of rules which aren't always legal. If you want to catch a taxi in the street, you often will have to shout your destination to the driver as he drives by.
If he is not going your direction, he may not stop to pick you up. This is standard practice in Athens and not regarded upon as rude. Just flag the next taxi you see.
Most of the times you will have an honest driver when you hail a taxi in Athens. However, there are some taxi-cowboys that will take advantage of tourists not knowing their way around.
Late at night, especially at athens airport, ferry stops, and bus and railroad stations, a driver may refuse to use his meter and demand an exorbitant fare. Smile, shake your head, and look for another cab.
They may even overcharge you, take on other passengers while driving you, make a big detour or drive you to a hotel they get a commission from. You want to play it safe?
Ask a few taxi drivers how much your ride is going to cost first so you will know the normal price, then get a taxi that charges that price. You want to pay for your drive, not buy the car....
According to the Greek legislation, upon your request, taxi drivers have to provide you with an official receipt for the amount paid for transportation services.
The receipt should also indicate the taxi registration number, the license plate and the driver's name.
If you do get overcharged in some way or other passengers are taken on board without your permission, don't start a fight but report the taxi scam to the police. They will deal with the cowboy.
As far as the taxi fares is concerned there are two basic tariffs, number 1 and number 2. Depending on the time of day and the journey, the driver must select the correct rate. Tariff 1 is the "day rate" used from 05:00 till midnight.
Tariff 2 is the night rate valid from midnight to 05:00. Tariff 1 is used within the city limits where the taxi is registered. Tariff 2 is used outside that zone. The number 1 or 2 should be clearly visible on the meter.