Should postcards be sent via registered mail?

We don’t recommend that.

Postcrossing is designed for ordinary letter-post. While registered/trackable services can be more reliable, they’re usually more expensive and often inconvenient for the recipient (as someone has to be home to sign during working hours, or make a cumbersome trip to the post office to pick it up). Registered mail may also trigger extra handling — and, in some countries, unnecessary customs checks or even additional fees.

All this extra fuss can turn a simple, joyful postcard into an errand... so we discourage the use of registered mail in Postcrossing.