Mailing N-400 form + other requirements

[Rice24]

What kind of envelope do I have to use to mail the n-400 form + other information (copy of green card, photo, and etc)

When I use a 9 x 4.5 envelope, I have to do a tri-fold on the stack of forms

Should I use a giant envelope to mail all the forms without folding it?

[rayb]

Use an envelope that doesn't require you to fold our documents. The Priority Main standard letter size has been my choice, with a $5.75 fee.

-Ray B

What kind of envelope do I have to use to mail the n-400 form + other information (copy of green card, photo, and etc)

When I use a 9 x 4.5 envelope, I have to do a tri-fold on the stack of forms

Should I use a giant envelope to mail all the forms without folding it?