Our standard letters are sent in a DL envelope but you are not restricted to using this size. We do also offer C5 envelopes where your letter is folded in half instead of 3 and A4 envelopes for those documents that you want to send unfolded. You can select the various envelope sizes from the down menu after writing your letter. In addition to this any letters that are too large for the DL envelope are automatically placed into the next size of envelope.