Whats the word again?

[Mariah Sanchez]

I am trying to word an email correctly, and only remember hearing the term used once before. I am trying to find the word for when you have say a 30 year fixed rate, with the stipulation that by say year ten the entire remaining balance is paid in lump. 

Thank You in Advance!

Also any objections to using this? Seller offered seller finance with 3% interest rate over 10 years. I was going to try and negotiate something similar to what I described above so that I can compete with the rental rates in the area.