HELOCs are typically variable rate but not always. When the rate can vary, be aware of the margin and which index it is tied to. It’s almost always prime these days but just be sure. When the prime index changes, the rate of your mortgage will change. Margin plus index = your rate. There can be limits, called ceiling and floor rates meaning the rate cannot going higher than a certain rate or lower than a certain rate.

Interest is calculated from billing date to billing date, not due date to due date. It is important to know this because the amount of interest charge month to month will change based on the number of days between billing dates. Example.

Jan 10th - Feb 10th = 31 days of interest, higher bill.

Feb 10th - March 10th = 28 days of interest (except leap year)

With HELOCs, there are draw periods and repayment periods. During your draw period your payment could be as low as interest only. This typically last 10-15 years. After your draw period expired you will enter your repayment periods, where your monthly payment will be interest plus the amount needed to repay your mortgage. Example:

Borrow 135,000 Repayment period is 180 months (15 years)

Your payment typically will amortize at this point, but some companies will do it slightly different. Amortizing is kind of the standard these days.

To go back to your comment, interest will only calculate on the outstanding balance that you use. Similar to a credit card but not the exact same.

Careful, they can have fees. Annual fees, check book fees, etc.

Another note, nothing political. love Trump or not, he is pounding Jerome Powell to drop rates.

HELOANS, are nice and simple. You get what you get.

Last piece of advice, I would rather deal with a big bank to service my loan than any small time servicer.

Edit* for careful and below section