When does Hajj become obligatory?

...and pilgrimage to the House is a duty owed to Allah by the people — **whoever is able to make his way there.**

Quran 3:97.

So the condition is one: istita'ah, capability. And Hajj is obligatory once in a lifetime:

Hajj is once. Whoever does more, it is voluntary.

Sunan Abi Dawud 1721; graded sound by the scholars. It is not in Sahih al-Bukhari or Muslim — though the same sense appears in Sahih Muslim 1337.

What capability includes

• Financial capability — the cost of going and returning, and enough maintenance left behind for the household. Hajj is not commanded by borrowing, or by leaving one's family hungry.
• Physical capability — being able to bear the journey.
• Safety of the route.
• Time — being able to arrive in the months of Hajj.

And on whether a mahram is a condition for a woman, the jurists differ — a condition for the Hanafi and Hanbali, with room for a trustworthy group for the Maliki and Shafi'i. There is evidence on both sides.

And the essential pillar of Hajj

Hajj is Arafah.

Jami at-Tirmidhi 889; Sunan an-Nasa'i 3016. Graded sound. Not Bukhari's or Muslim's. One who did not stand at Arafah has no Hajj — and Umrah has no Arafah at all, which is the greatest difference between the two.

Today's question

Quotas, waiting lists of years, and Hajj on borrowed money — there is detail on these, and the answer turns on circumstances. Describe your situation — wealth, health, family duties — to a qualified mufti.

This is educational, not a fatwa.