\documentclass[10pt]{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[left=0.5cm,right=0.5cm,top=0.5cm,bottom=0.5cm,noheadfoot,nomarginpar,showframe]{geometry}
\usepackage{lmodern}
\usepackage{tabularx}
\usepackage{tabu}
\usepackage{multirow}
\usepackage{graphicx}
\renewcommand{\familydefault}{\sfdefault}
\setlength{\extrarowheight}{3pt}

\begin{document}
\footnotesize

\pagestyle{empty}

\begin{center}
\begin{tabularx}{\textwidth}{XXXX}

&&& \\
\multicolumn{4}{l}{\bf \large Faktúra: \hfill {{invoice.number}}} \\
&&& \\ \hline
\multicolumn{2}{X|}{} & \multicolumn{2}{X}{} \\
\multicolumn{2}{l|}{\bf Dodávateľ:} & \multicolumn{2}{X}{\bf Odberateľ} \\
\multicolumn{2}{X|}{} & \multicolumn{2}{X}{} \\

\multicolumn{2}{l|}{\large\bf {{issuer.name}}} & \multicolumn{2}{l}{\large\bf {{customer.name}}} \\
{{py:
a1 = issuer.address[:]
a2 = customer.address[:]
a1 += (len(a2)-len(a1))*[""]
a2 += (len(a1)-len(a2))*[""]
}}
{{for f1, f2 in zip(a1, a2)}}
\multicolumn{2}{l|}{\large {{f1}}} & \multicolumn{2}{l}{\large {{f2}}} \\
{{endfor}}

% COMPANY ID NUMBERS
\multicolumn{2}{X|}{} & \multicolumn{2}{X}{} \\
    \multicolumn{2}{l|}{IČO: {{issuer.ico}}} & \multicolumn{2}{l}{IČO: {{if customer.icdph}}\hspace{0.3cm}{{endif}} {{customer.ico}}} \\
    \multicolumn{2}{l|}{DIČ: {{issuer.dic}}} & \multicolumn{2}{l}{DIČ: {{if customer.icdph}}\hspace{0.3cm}{{endif}} {{customer.dic}}} \\
{{if issuer.icdph or customer.icdph}}
    {{if issuer.icdph}}
    \multicolumn{2}{l|}{IČDPH: {{issuer.icdph}}} &
    {{else}}
    \multicolumn{2}{l|}{Neplatca DPH} &
    {{endif}}
    {{if customer.icdph}}
    \multicolumn{2}{l}{IČDPH: {{customer.icdph}}} \\
    {{else}}
    \multicolumn{2}{l}{} \\
    {{endif}}
{{endif}}

\multicolumn{2}{X|}{} & \multicolumn{2}{X}{} \\

% Comments
{{py:
a1 = issuer.comments[:]
a2 = customer.comments[:]
a1 += (len(a2)-len(a1))*[""]
a2 += (len(a1)-len(a2))*[""]
}}
{{for f1, f2 in zip(a1, a2)}}
\multicolumn{2}{l|}{ \footnotesize {{f1}} } & \multicolumn{2}{l}{ \footnotesize {{f2}} } \\
{{endfor}}
\multicolumn{2}{X|}{} & \multicolumn{2}{X}{} \\

\multicolumn{2}{l|}{\bf Platobné podmienky:} & & \\
Forma úhrady:      & \multicolumn{1}{l|}{ {{"v~hotovosti" if invoice.payment=="cash" else "prevodom"}}} & & \\
IBAN:              & \multicolumn{1}{l|}{ {{issuer.iban}}}    & Dátum vystavenia: & \multicolumn{1}{r}{ {{invoice.issued.strftime("%d.%m.%Y")}}} \\
SWIFT/BIC:         & \multicolumn{1}{l|}{ {{issuer.swift}} }  & \multicolumn{2}{l}{Dátum dodania: \hfill {{invoice.delivered.strftime("%d.%m.%Y")}}} \\
Variabilný symbol: & \multicolumn{1}{l|}{ {{invoice.number}}} & \multicolumn{2}{l}{\large\bf Dátum splatnosti: \hfill {{invoice.due.strftime("%d.%m.%Y")}}} \\
% COMMENTS
{{if invoice.notes}}
\multicolumn{2}{X|}{} & \multicolumn{2}{X}{} \\ \hline
& & & \\
\bf Poznámky: & & & \\[1em]
{{for note in invoice.notes}}
\multicolumn{4}{l}{\large {{note}}} \\
{{endfor}}
{{endif}}

\multicolumn{2}{X|}{} & \multicolumn{2}{X}{} \\ \hline

& & & \\

\multicolumn{4}{l}{\bf Faktúrujeme Vám za služby podľa Rámcovej zmluvy} \\

& & & \\

% ITEMS
\multicolumn{4}{X}{%
    \hspace*{-1.35\tabcolsep}
    \begin{tabu} to \textwidth {%
            >{\hsize=2.5\hsize}X[l]%
            >{\hsize=0.5\hsize}X[r]%
            >{\hsize=0.5\hsize}X[r]%
            >{\hsize=0.5\hsize}X[r]%
            >{\hsize=0.5\hsize}X[r]}
        \normalsize \bf Popis položky & \bf Množstvo & \bf MJ & \bf Cena za MJ & \bf Celková cena \\
        {{for item in invoice.items}}
        {{item[0]}} & {{item[1]}} & {{item[2]}} & {{eur(item[3])}} & {{eur(item[1] * item[3])}} \\
        {{endfor}}
    \end{tabu}
} \\

%& & & \\
%\hline
%& & & \\
%\multicolumn{3}{l}{\large\bf Celkom k úhrade:} & \multicolumn{1}{r}{\large\bf {{eur(invoice.sum)}} } \\
& & & \\
\hline
\multicolumn{4}{r}{} \\
%\multicolumn{4}{r}{\includegraphics[scale=1]{../signature.jpg}\hspace{.4cm} } \\
\end{tabularx}
\end{center}

\vfill

% Footer
\centering
\begin{tabu} to \textwidth {XX|XX|X|X[r]}
\hline
    Vyhotovil: Peter Hatina && Prevzal: && Celková suma: & {{eur(invoice.sum)}} \\ \cline{5-6}
    \multirow{2}{*}{\hspace*{1.0cm}\includegraphics[scale=0.3]{../signature.jpg} } && && Uhradené zálohami: & {{eur(invoice.advance)}} \\ \cline{5-6}
    && && Zostáva uhradiť: & {{eur(invoice.topay)}} \\ \cline{5-6}
    && && & \\
    && && \multirow{-2}{*}{K úhrade:} & \multirow{-2}{*}{ \bf \large {{eur(invoice.topay)}}\phantom} \\
\end{tabu}

\end{document}