DK Hostmaster administers a database of all .dk domain names. It is kind of like a telephone book containing domain names instead of telephone numbers.
You can always use our whois database to look up whether a given domain name is registered and to whom.
There are 1.3 million registered .dk domain names and we have direct contact with our 700,000 customers. Our customer service helps up to 1,000 customers every day with the administration of their domain names.