Will a domain name registrar take my domain name if I forget to renew it?

Short answer: Yes!

A domain name is initially registered for a period of 1-10 years. If you register a domain name today (Feb. 4, 2007) for the common term on 1 year, the expiration date will be Feb. 4, 2008.

Once a domain name has passed its expiry date, a number of things happen. Firstly, the domain name is typically put on hold - that is, its name server information is deleted or modified so that the domain name no longer points to the website it is associated with. Secondly, the domain name is put in the registrar's deletion queue for processing according to its procedures for handling expiring domains (as mentioned previously, these vary significantly from registrar to registrar)

Some registrars give customers very little leeway, choosing to delete domain names within ten days of the expiry date. Others hold on to names for longer periods, typically 30 or 45 days. Still others don't release domain names back into the pool at fixed intervals, but in large batches at irregular intervals.

Most registrars will send you several emails before the domain name is actually deleted. If you fail to receive these emails because your whois information is outdated, or you just procrastinate it long enough, you will lose this domain name. If it is a premium generic domain name it will probably be snatched up by one of the many dropcatchers, ie, Snapnames.com, Pool.com, Godaddy.com, etc.

ALWAYS REMEMBER TO RENEW YOUR DOMAIN NAMES AT LEAST 1-2 MONTHS BEFORE THE EXPIRATION DATE!

Certain portions of this blog have been taken from: Igoldrush.com