Advertisement — in-article
A HELOC has two distinct phases, and confusing them is the most common HELOC mistake.
The draw period
Usually about 10 years. You can borrow, repay and re-borrow up to your limit, and most lenders let you pay interest only. Payments feel small because you're not touching principal.
The repayment period
Often 20 years. The line closes to new borrowing and you repay principal plus interest, so the monthly payment can jump sharply — sometimes doubling. Prepare by paying some principal early. See the size of the jump on the HELOC payment calculator.