Proof of funds letter to speak to agent

[Bhanu Kuna]

Hi everyone! I'm building my core 4 and contacted an agent and he asked for proof of funds letter before speaking. Can anyone explain what the purpose of the proof funds letter is at this point? What's the best method for getting the letter? I have 25k a can draw from my HELOC and few thousand in the bank. I think if I apply I should easily be able to get the letter.

Thanks! I'd really like to get a better understanding of the process.