Subscription to our DAC services gives access to both the time delay DAC and the real time DAC.

The time delay DAC allows a high volume of domain name queries, however returns data with a 100ms delay. The time delay DAC is ideal for registrars with a large customer base that process a large volume of domain name queries on a regular basis. Due to the small delay, this service is suited to non-time critical queries such as searching for suitable alternative or complementary domain names in response to customer requirements.

Access limits

Access to the time delay DAC is based on business levels using the formula shown:

This calculation is capped at a maximum of 3 million daily lookups.

Using the highest monthly new registration figure gives a degree of stability to access levels. Limits are recalculated at the start of the month. Full details about limits and query rates are available in the time delay DAC acceptable use policy.

The access limits have been set to provide registrars with an appropriate volume of lookups dependant on their size and requirements. We may review these limits and the calculation used once the service has been thoroughly tested and the load impact fully assessed.

The time delay DAC is available at dac.nic.uk on port 2043. Full instructions for use are available.