Miksa was the youngest of four children born to religious Jewish parents. The Deutches lived in the town of Bistrita in Transylvania, a region of Romania that belonged to Hungary until 1918. After 1910, the family lived in nearby Viseu de Sus. In 1922 Miksa moved to Budapest, Hungary, where he and his older brother, Pal, opened a business selling matches. In 1928 Miksa married Kornelia Mahrer.
1933-39: Miksa and Kornelia had three children, whom they raised with a religious education. Miksa and his brother were the sole distributors in Hungary of Swedish-made matches, and the business prospered. In May 1939 the Hungarian government enacted a law that limited the number of Jews who could be employed in Hungarian businesses, forcing Miksa to fire some of his Jewish employees.
1940-44: In 1940 Miksa was conscripted into the Hungarian army's labor service. Two years later, he was forced to surrender control of his business to a brother of the Hungarian prime minister. In October 1944 Miksa began to fear deportation, and he briefly left his labor unit to visit his wife, who gave him a Swedish safe-conduct pass she had received from a friend. When Miksa returned to the factory on October 31, a Hungarian officer tore up his pass and ordered him deported along with the others.
On November 10, 1944, Miksa wrote to his wife that he was being force-marched from Hungary to Austria. He died in the Mauthausen concentration camp in Austria at the age of 47.