Yūbin Net is a Japanese postal-code search service designed to make finding postal information straightforward for people of all ages and useful for business tasks. Users can search for an address from a postal code, find a postal code using a place name or other keywords, and look up locations for organizations such as companies, schools, and hotels. Search options include browsing by prefecture and searching general or business-office postal codes. The site lists 124,827 general postal-code records and 22,427 business-office records.

Its data is based on the latest postal-code directory published by Japan Post and is updated monthly; the site reports using data issued on August 31, 2026. Yūbin Net has provided its service since 2000 and also offers information about a free Windows postal-code search application called Yūka. The site is managed by D-Net Co., Ltd. and clearly states that it is not operated by Japan Post or the postal service. Additional site features include downloadable wallpapers and illustrations, along with a feedback channel and privacy information.