1. Test File (containing real zip codes or xxxxx in the place of numerals for zip codes)
  2. Sample Document
  3. New Letter Code
  4. Mapping instructions of the data file variables of where they’re to appear on the letter

Note: It’s also helpful if you let customer service know if the letter will need additional items like a business reply envelope, the color in you want to use (black, black with highlight blue, full color, paper size (letter or legal), paper type (white, tutti fruiti, perforation, non-perforation, simplex/duplex).