In 1635, he accepted Dutch letters of marque despite being in the employ of the Providence Island Company and, from 1636 to 1641, acted as a privateer for the English trading company.
Although briefly returning to Providence to assist the island's defense against Spanish attacks in 1636, Axe had a successful privateering career delivering a captured prize, with cargo including gold, silver, jewels, indigo and cochineal, as he returned to England in May 1640.
Following the capture of Providence by the Spanish in 1641, the Providence Island Company was dissolved. Escaping to St. Kitts, Axe later took part in a privateering expedition under Captain William Jackson to the West Indies from 1642 to 1645, in which the privateers managed to capture Kingston, Jamaica.