I just know I’m going to make this sound more complicated than it is. Forgive me.

The country code for Nederland is +31, where the ‘+’ stands for the international access code for where you’re calling from. Example: from the US that’s 011. From within Europe or the UK it’s 00.

Amsterdam’s city code for land lines is 020. The code for all Dutch mobile phones is 06. Calling from one Dutch phone to another, you keep the leading zero in the area code. If you’re phoning into NL from abroad, you drop the leading zero.

Therefore, to call ...

from to an Amsterdam house phone to a Dutch mobile
a Dutch phone 020 xxx xxxx 06 xxxx xxxx
US 011 31 20 xxx xxxx 011 31 6 xxxx xxxx
Europe or UK 00 31 20 xxx xxxx 00 31 6 xxxx xxxx

Conversely, to phone from Amsterdam to London: 00 44 20 xxxx xxxx. And to phone from Amsterdam to Boston MA: 00 1 617 xxx xxxx.

Of course if you’re walking around Amsterdam with a foreign mobile phone, your ‘local’ calls get pretty expensive. That’s why some short-term visitors pick up a local pre-paid mobile phone from one of the many phone shops around town. In fact I’ve known people who lived here for years with pre-paid mobiles, occasionally topping up their value at the Albert Heijn supermarket desk.

The thing is, to start a real phone account here — or any utility account for that matter — you need to have a Dutch bank account and a local residence address. And that gets us into the whole bureaucratic marmalade of migrating to Amsterdam. More about that elsewhere.