All investors have a borrowing power wall that is the maximum lenders are willing to lend to.
There are techniques to expand borrowing capacities like removing credit cards and deploying a structured investment lending. These can help expand capacities to a point, but they do have restrictions as to how far they can take property investors.
For those advanced property investors, should you wish to build massive investment portfolios and continue to accumulate over time, there is no substitute to increasing your income over time. Below we have modelled out maximum borrowing capacities for different income profiles (for a couple) to illustrate the power of increasing income. The upside is, increasing income has no real upper bound (just ask Mark Zuckerberg!).