The major role of the TIC is to identify the sources or location of information and/or materials, process them in a timely fashion and transform them into the right format to serve the varied needs of the users (information repackaging). The types of documents collected by the Thailand Information Center include research reports, monographs, surveys, articles from magazines and periodicals, maps, theses and dissertations, speeches, trip reports, symposium and conference proceedings, bibliographies, statistical yearbooks and other comparable items. The principal sources of documents acquired are the Royal Thai Government and foreign agencies. Other sources include foundations, UN agencies, international organisations, professional societies, libraries of the Thai Government and commercial banks, Thai and foreign universities, private sector and state enterprises, religious and non-governmental agencies, and so on. Many documents have also been obtained from the private collections or through the donations of research scholars themselves.

At present, the collection consists of approximately 80,000 indexed items. Seventy (70) percent of the documents in the TIC collection are written in English language, 25 percent in Thai and five percent are written in both languages. In regard to the approach to indexing used at the TIC, there is no formal classification scheme in the system, such as the Dewey Decimal or Universal Decimal classification. The TIC uses only a controlled index vocabulary in direct-reading without hierarchical, numerical coding. Anyhow, the TIC is presently using "MACROTHESAURUS" for Information Processing in the Field of Economic and Social Development, belonged to the United Nations Organisation for Economic Co-operation and Development (OECD), as a handbook for its indexing and information retrieval. A thesaurus is an indexing language made up of words or noun phrases (known as descriptors) which is used for the assigning of index terms to documents, so that documents in the collection may be retrieved by the combination (or post-coordination) of selected descriptors, chosen at the search stage. The thesaurus is thus the most efficient and accurate indexing method resulting with the high precision and specific result in information process and retrieval.

Another unique characteristic of the TIC system is that an indicative abstract of approximately 100 words written in English language is provided for every document in its collection so as to enable its users to select more knowledgeably the documents they may wish to examine. The indicative abstract should enable the reader to identify the basic content of a document quickly and accurately, and thus to decide whether or not he/she needs to read the document itself. This abstract, accurate representation of a document, contains no added interpretations or criticisms. It does not consist of an extract, summary, or synopsis of the document but serves as a guide to the contents of the document. Anyway, this indicative abstract is not self-contained and cannot be used in lieu of the document itself.