Insert Address data into the next row down from a user form.

Ok for some firms to have multiple address lines, but what exactly are you trying to achieve in that case ?
On your userform you only have 1 textbox for an address line so ..... ?
After giving it some thought I guess you want the possibility to select an address line in case of multiple addresses.
A solution would be to change TextBox to Combobox and check for multiple address lines and add them accordingly to the Combobox.
Does this sound plausible to you ?
Post an example file where this situation occurs so we can work with that.