Let's start of with an minimal example - something that really helps the community, regardless of what you may think, really. The following is taken from the KOMA-script documentation (section 4.20. Closing, p 190):
\documentclass[foldmarks=true,foldmarks=blmtP,
fromphone,fromemail,fromlogo,
subject=titled,
version=last]{scrlttr2}% http://ctan.org/pkg/koma-script
\usepackage[english]{babel}% http://ctan.org/pkg/babel
\usepackage{graphicx}% http://ctan.org/pkg/graphicx
\begin{document}
\setkomavar{fromname}{John Public}
\setkomavar{signature}{John Public\\
(former chairman)}
\renewcommand*{\raggedsignature}{\raggedright}
\setkomavar{fromaddress}{Valley 2\\
54321 Public-Village}
\setkomavar{fromphone}{0\,12\,34~56\,78}
\setkomavar{fromemail}{Peter@Public.invalid}
\setkomavar{fromlogo}{\includegraphics[height=5\baselineskip]{tiger}}
\setkomavar{location}{\raggedright
Club nember no.~4711\\
since 11.09.2001\\
chairman 2003--2005}
\setkomavar{date}{29th February 2011}
\setkomavar{place}{Public-Village}
\setkomavar{subject}{Missing general meeting}
\begin{letter}{%
Joana Public\\
Hillside 1\\
12345 Public-City%
}
\opening{Dear chairman,}
the last general meeting was about one year ago.
I want to remind you, that the constitution of our
club advises you to make a general meeting every
six month. Because of this I expect the executive
board to detain such a meeting immediately.
\closing{Expecting an invitation}
\ps PS: I hope you accept this as an friendly
demand note.
\setkomavar*{enclseparator}{Enclosure}
\encl{Compendium of the constitution with the
general meeting paragraphs.}
\cc{executive board\\all members}
\end{letter}
\end{document}
This is what the output looks like:

If we wish to modify the structure of the \closing
, we should modify what is contained within the \parbox
command. Let's do this using etoolbox
in the form of a \patchcmd
:
\usepackage{etoolbox}% http://ctan.org/pkg/etoolbox
\makeatletter
\patchcmd{\closing}% <cmd>
{\parbox}% <search>
{\parbox{\linewidth}{\raggedsignature\strut\ignorespaces\let\\\relax%
#1 \usekomavar{signature}}%
\@gobbletwo}%< <replace>
{}{}% <success><failure>
\makeatother
The above code replaces \parbox
for \parbox{..}{...}\@gobbletwo
. The replacement \parbox{..}{...}
uses elements of the older \parbox
, but doesn't insert a sigbeforevskip
length that used to produce the vertical gap. Instead, \usekomavar{signature}
is set with a space between the actual \closing{#1}
. Also, \\
is \let
to \relax
(but might not be necessary) to avoid forced paragraph breaks. The latter \@gobbletwo
eats the old \parbox
's two arguments.
Here's an example document showing the output results (note that I've also moved a \ps
below \encl
and \cc
, as requested):

\documentclass[foldmarks=true,foldmarks=blmtP,
fromphone,fromemail,fromlogo,
subject=titled,
version=last]{scrlttr2}% http://ctan.org/pkg/koma-script
\usepackage[english]{babel}% http://ctan.org/pkg/babel
\usepackage{graphicx}% http://ctan.org/pkg/graphicx
\usepackage{etoolbox}% http://ctan.org/pkg/etoolbox
\makeatletter
\patchcmd{\closing}% <cmd>
{\parbox}% <search>
{\parbox{\linewidth}{\raggedsignature\strut\ignorespaces\let\\\relax%
#1 \usekomavar{signature}}%
\@gobbletwo}%< <replace>
{}{}% <success><failure>
\makeatother
\begin{document}
\setkomavar{fromname}{John Public}
\setkomavar{signature}{John Public\\
(former chairman)}
\renewcommand*{\raggedsignature}{\raggedright}
\setkomavar{fromaddress}{Valley 2\\
54321 Public-Village}
\setkomavar{fromphone}{0\,12\,34~56\,78}
\setkomavar{fromemail}{Peter@Public.invalid}
\setkomavar{fromlogo}{\includegraphics[height=5\baselineskip]{tiger}}
\setkomavar{location}{\raggedright
Club nember no.~4711\\
since 11.09.2001\\
chairman 2003--2005}
\setkomavar{date}{29th February 2011}
\setkomavar{place}{Public-Village}
\setkomavar{subject}{Missing general meeting}
\begin{letter}{%
Joana Public\\
Hillside 1\\
12345 Public-City%
}
\opening{Dear chairman,}
the last general meeting was about one year ago.
I want to remind you, that the constitution of our
club advises you to make a general meeting every
six month. Because of this I expect the executive
board to detain such a meeting immediately.
\closing{Expecting an invitation}
\setkomavar*{enclseparator}{Enclosure}
\encl{Compendium of the constitution with the
general meeting paragraphs.}
\cc{executive board\\all members}
\ps PS: I hope you accept this as an friendly
demand note.
\end{letter}
\end{document}
Of course, other adjustments can also be made.
\signature
command. What does this do and where is it defined? – cfr Jan 12 '14 at 20:46\closing
along with\signature
of course, and both the\cc
&\encl
in the footer of the scrlttr2 (as I use it to form an Invoice). I have partially achieved this by customising heasymTypB.lco
file (by Markus Kohm). I plan to update my (directly related) question & answer: tex.stackexchange.com/q/151437/8272. Anyhow, leaving the koma variablesclosing
&signature
empty is not practical I think. I like the idea of an Invoice Template with the usual stuff already written, then fill in details. – Nikos Alexandris Jan 13 '14 at 16:31