Sun in the 12th house (Vyaya, the house of loss & liberation) brings the significations of Sun, namely soul (atma), father, authority & government, into the area of expenditure, foreign lands, isolation and spiritual liberation. The 12th house governs expenditure & loss, moksha & liberation, foreign lands, isolation & retreat.
Results of Sun in the 12th House
Sun is a malefic planet, so here it tends to bring low confidence, ego conflicts, trouble with father or bosses, and weak vitality focused on expenditure, foreign lands, isolation and spiritual liberation. As the 12th is a dusthana (difficult) house, results may come through struggle before growth.The exact result depends on which sign Sun occupies here and the aspects it receives.
When It Activates
These results typically surface during the Vimshottari mahadasha or antardasha of Sun, and when transiting planets trigger the 12th house. A well-placed Sun here supports spiritual growth, gains from abroad and healthy detachment; when afflicted it can indicate heavy expenses, losses, isolation and hidden enemies.