الحج is not واجب if debts prevent financial ability, but if you can maintain payments while affording الحج, many scholars permit it — seek creditor permission when possible.
The question of الحج with debts requires careful consideration of the Islamic principle of istita'ah (ability), which is a condition for الحج to become واجب. The majority of scholars across all four madhahib agree that if a person has debts that prevent them from meeting their financial obligations, الحج is not yet واجب for them — they should prioritize debt repayment. The rights of creditors are a serious matter in Islam.
However, the situation is more nuanced for people with long-term structured debts (mortgages, student loans, installment plans). If you can afford the الحج expenses while maintaining your regular payment schedule without defaulting, many contemporary scholars permit performing الحج. The Hanafi position tends to be more flexible on this, while the Hanbali position is stricter about clearing debts first. It is strongly مستحب to seek written permission from creditors and to make a written will before traveling in case anything happens. For voluntary (nafl) الحج — meaning you have already performed your واجب الحج — scholars unanimously advise paying off debts first.
Source: ابن قدامة, al-Mughni; al-Nawawi, al-Majmu'; al-Kasani, Bada'i al-Sana'i