Is it permissible for a tourism agency to substitute for a woman's mahram if she wishes to perform 'Umrah without her husband?

An agency does not take the place of a husband or a mahram when a woman travels, as their presence is a condition for her travel, based on the Prophet's (peace and blessings be upon him) saying: "A woman may not travel except with a mahram."

If the ‘Umrah is obligatory, she may travel without a husband or mahram if the company is trustworthy. However, if it is a voluntary ‘Umrah, she is not permitted to travel except with her husband's permission and in his company or the company of a mahram.