Which loan type allows a borrower to increase the loan amount up to a determined limit?

An open-end loan is a type of financing that allows a borrower to increase the loan amount up to a predetermined limit as needed. This type of loan works similarly to a line of credit, where the borrower has access to a set amount of funds, can withdraw from it, repay it, and then borrow again, up to the maximum limit established in the loan agreement. This flexibility can be very advantageous, especially for borrowers who may need varying amounts of funds over time.

In contrast, a fixed-rate loan offers the borrower a specific amount at a fixed interest rate for the life of the loan, with no ability to draw additional funds beyond the original loan amount. Similarly, a home equity loan provides a lump sum based on the equity in the borrower's home, but it does not allow for future borrowing against that same loan amount once it is secured. A convertible loan typically refers to a loan that can be converted from one type to another, often seen in situations with variable rates changing to fixed rates, but it does not specifically relate to increasing the loan amount.

Therefore, the defining feature of an open-end loan is its capacity for borrowers to access additional funds within established limits, making it the best choice for this question.