ORGANIZATION	6 Months Ended
Sep. 30, 2011
Organization, Consolidation and Presentation Of Financial Statements [Abstract]
Organization, Consolidation and Presentation Of Financial Statements Disclosure [Text Block]	NOTE A - ORGANIZATION Boston Capital Tax Credit Fund III L.P. (the "Fund") was formed under the laws of the State of Delaware as of September 19, 1991 for the purpose of acquiring, holding, and disposing of limited partnership interests in operating partnerships which will acquire, develop, rehabilitate, operate and own newly constructed, existing or rehabilitated low-income apartment complexes ("Operating Partnerships"). Effective as of June 1, 2001 there was a restructuring, and as a result, the Fund's general partner was reorganized as follows. The general partner of the Fund continues to be Boston Capital Associates III L.P., a Delaware limited partnership. The general partner of the general partner of the Fund is now BCA Associates Limited Partnership, a Massachusetts limited partnership, whose sole general partner is C&M Management, Inc., a Massachusetts corporation whose limited partners are Herbert F. Collins and John P. Manning. Mr. Manning is the principal of Boston Capital Partners, Inc. The limited partner of the general partner is Capital Investment Holdings, a general partnership whose partners are various officers and employees of Boston Capital Partners, Inc. and its affiliates. The assignor limited partner is BCTC III Assignor Corp., a Delaware corporation which is wholly-owned by Herbert F. Collins and John P. Manning. Pursuant to the Securities Act of 1933, the Fund filed a Form S-11 Registration Statement with the Securities and Exchange Commission, effective January 24, 1992 which covered the offering (the "Public Offering") of the Fund's beneficial assignee certificates ("BACs") representing assignments of units of the beneficial interest of the limited partnership interest of the assignor limited partner. The Fund registered 20,000,000 BACs at $10 per BAC for sale to the public in one or more series. On September 4, 1993 the Fund filed an amendment to Form S-11 with the Securities and Exchange Commission which registered an additional 2,000,000 BACs at $10 per BAC for sale to the public in one or more series. The registration for the additional BACs became effective on October 6, 1993. Offers and sales of BACs in Series 15 through 19 of the Fund were completed and the last of the BACs in Series 15, 16, 17, 18 and 19 were issued by the Fund on September 26, 1992, December 28, 1992, September 17, 1993, September 22, 1993, and December 17, 1993, respectively. The Fund sold 3,870,500 of Series 15 BACs, for a total of $38,705,000; 5,429,402 of Series 16 BACs, for a total of $54,293,000; 5,000,000 of Series 17 BACs, for a total of $50,000,000; 3,616,200 of Series 18 BACs, for a total of $36,162,000; and 4,080,000 of Series 19 BACs, for a total of $40,800,000. As of June 30, 2011 5,427,602 BACs in Series 16 are outstanding. The Fund issued the last BACs in Series 19 on December 17, 1993. This concluded the Public Offering of the Fund.

ORGANIZATION

6 Months Ended

Sep. 30, 2011

Organization, Consolidation and Presentation Of Financial Statements [Abstract]

Organization, Consolidation and Presentation Of Financial Statements Disclosure [Text Block]

NOTE A - ORGANIZATION

Boston Capital Tax Credit Fund III L.P. (the "Fund") was formed under the laws of the State of Delaware as of September 19, 1991 for the purpose of acquiring, holding, and disposing of limited partnership interests in operating partnerships which will acquire, develop, rehabilitate, operate and own newly constructed, existing or rehabilitated low-income apartment complexes ("Operating Partnerships"). Effective as of June 1, 2001 there was a restructuring, and as a result, the Fund's general partner was reorganized as follows. The general partner of the Fund continues to be Boston Capital Associates III L.P., a Delaware limited partnership. The general partner of the general partner of the Fund is now BCA Associates Limited Partnership, a Massachusetts limited partnership, whose sole general partner is C&M Management, Inc., a Massachusetts corporation whose limited partners are Herbert F. Collins and John P. Manning. Mr. Manning is the principal of Boston Capital Partners, Inc. The limited partner of the general partner is Capital Investment Holdings, a general partnership whose partners are various officers and employees of Boston Capital Partners, Inc. and its affiliates. The assignor limited partner is BCTC III Assignor Corp., a Delaware corporation which is wholly-owned by Herbert F. Collins and John P. Manning.

Pursuant to the Securities Act of 1933, the Fund filed a Form S-11 Registration Statement with the Securities and Exchange Commission, effective January 24, 1992 which covered the offering (the "Public Offering") of the Fund's beneficial assignee certificates ("BACs") representing assignments of units of the beneficial interest of the limited partnership interest of the assignor limited partner. The Fund registered 20,000,000 BACs at $10 per BAC for sale to the public in one or more series. On September 4, 1993 the Fund filed an amendment to Form S-11 with the Securities and Exchange Commission which registered an additional 2,000,000 BACs at $10 per BAC for sale to the public in one or more series. The registration for the additional BACs became effective on October 6, 1993. Offers and sales of BACs in Series 15 through 19 of the Fund were completed and the last of the BACs in Series 15, 16, 17, 18 and 19 were issued by the Fund on September 26, 1992, December 28, 1992, September 17, 1993, September 22, 1993, and December 17, 1993, respectively. The Fund sold 3,870,500 of Series 15 BACs, for a total of $38,705,000; 5,429,402 of Series 16 BACs, for a total of $54,293,000; 5,000,000 of Series 17 BACs, for a total of $50,000,000; 3,616,200 of Series 18 BACs, for a total of $36,162,000; and 4,080,000 of Series 19 BACs, for a total of $40,800,000. As of June 30, 2011 5,427,602 BACs in Series 16 are outstanding. The Fund issued the last BACs in Series 19 on December 17, 1993. This concluded the Public Offering of the Fund.