Once a mark is considered a candidate for adoption, searches must be conducted to ensure that third parties do not have adverse claims of prior rights to the mark. A growing business that has used a trademark for awhile and, in expanding, finds itself threatened with a trademark infringement suit by a senior trademark owner will face extensive marketing and legal costs which could be easily avoided in advance.

Searching in countries outside of the United States differs greatly from searching within the United States. Very few countries, with the exception of Canada and the United Kingdom, have any reliable form of "common law" or “user” search, such as is available in the United States. In addition, the accuracy of trademark registers varies considerably by country. In many developing countries, searches are conducted manually by leafing through index cards or booklets with pages of applications, since the trademark offices are not computerized. In other countries it may not be possible to search for conflicting pending applications or the time lag between the filing of an application and the entry of the particulars onto the search database may be so long that significant "black out" periods exist. Searching device or “logo” trademarks also presents great difficulties in many countries.

Deciding in which countries to conduct availability searches is heavily dependent upon the marketing plans of the individual trademark. If products bearing the trademark will be readily available in many foreign countries simultaneously, then searches of those countries in which the product will immediately appear may be appropriate. On the other hand, if the product is to be introduced gradually into foreign markets, it may be more cost-effective to forego searching in many countries in favor of simply filing applications and addressing third party objections as they arise. Many different types of searches, from "knockout" identity searches to full availability searches may be available and should be considered as appropriate on a case by case basis.

In order to conduct a proper search, it is important that the correct search parameters be determined. The correct search parameters for each mark will also be determined on a case by case basis. Relevant considerations will depend on the proposed use of the mark, the possible ancillary uses and related uses of the proposed mark, the elements of the mark at issue, etc. The inability to craft a careful search may lead to disastrous consequences, particularly in foreign countries where search results, and their interpretation, may differ vastly from search results in the United States.

Crafting proper search parameters is only the first step in searching. Once the search results are obtained, they must be interpreted and should be reviewed by experienced trademark counsel, since it is possible for the inexperienced practitioner to overlook many subtle features of a search. Not only must the reviewer analyze and compare marks with one another, which involves a great deal of subjective comparison based on experience in dealing with trademark matters, but the goods and services under each of the references that are revealed must be considered. A similar mark that is registered in respect of seemingly dissimilar goods may not be considered relevant to the uninitiated, but may be germane in the eyes of the trademark practitioner. This is especially so in foreign countries, where tests for confusion differ widely and search results may be interpreted far differently than in the United States. Additional problems arise when marks revealed in foreign searches consist of foreign terms or trademarks in non-Roman alphabets, such as in Chinese, Japanese, Cyrillic, Greek, Hebrew, Arabic, etc.

In addition to regular trademark register searches, a search of the Internet for conflicting domain name registrations should also be conducted. Also possible is a search of the Internet using a commercially available search engine for conflicting websites.

Even if a party has commenced use of their mark in the United States, foreign searches may be advisable to ensure that as that party's activities grow they are not confronted with a third party with senior rights who may object to, or enjoin, their use of the trademark.