\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}

{{if invoice.translate}}
\newcommand\translation[1]{/\textit#1}
{{else}}
\newcommand\translation[1]{}
{{endif}}
\newcommand\translatable[2]{#1\translation#2}
\newcommand\translatablebf[2]{\textbf{#1}\translation#2}

\def\InvoiceSK{Faktúra}
\def\InvoiceEN{Invoice}
\def\ClientSK{Odberateľ}
\def\ClientEN{Client}
\def\SupplierSK{Dodávateľ}
\def\SupplierEN{Supplier}
\def\PaymentTermsSK{Platobné podmienky}
\def\PaymentTermsEN{Terms of payment}
\def\PaymentMethodSK{Forma úhrady}
\def\PaymentMethodEN{Payment method}
\def\PaymentMethodCashSK{v~hotovosti}
\def\PaymentMethodCashEN{cash}
\def\PaymentMethodBankTransferSK{prevodom}
\def\PaymentMethodBankTransferEN{bank transfer}
\def\IssueDateSK{Dátum vystavenia}
\def\IssueDateEN{Issue date}
\def\DeliveryDateSK{Dátum dodania}
\def\DeliveryDateEN{Delivery date}
\def\DueDateSK{Dátum splatnosti}
\def\DueDateEN{Due date}
\def\VariableSymbolSK{Variabilný symbol}
\def\VariableSymbolEN{Variable symbol}
\def\NotesSK{Poznámky}
\def\NotesEN{Notes}
\def\SubjectSK{Popis položky}
\def\SubjectEN{Subject}
\def\AmountSK{Množstvo}
\def\AmountEN{Amount}
\def\UnitSK{MJ}
\def\UnitEN{Unit}
\def\UnitPriceSK{Cena za MJ}
\def\UnitPriceEN{Unit price}
\def\TotalPriceSK{Celková cena}
\def\TotalPriceEN{Total price}
\def\TotalAmountSK{Celková suma}
\def\TotalAmountEN{Total amount}
\def\IssuedBySK{Vystavil}
\def\IssuedByEN{Issued by}
\def\AdvancesPaidSK{Udradené zálohami}
\def\AdvancesPaidEN{Advances paid}
\def\TotalDueSK{K~úhrade}
\def\TotalDueEN{Total due}
\def\Invoice{\translatablebf\InvoiceSK\InvoiceEN}
\def\Supplier{\translatablebf\SupplierSK\SupplierEN}
\def\Client{\translatablebf\ClientSK\ClientEN}
\def\PaymentTerms{\translatablebf\PaymentTermsSK\PaymentTermsEN}
\def\PaymentMethod{\translatable\PaymentMethodSK\PaymentMethodEN}
\def\PaymentMethodCash{\translatable\PaymentMethodCashSK\PaymentMethodCashEN}
\def\PaymentMethodBankTransfer{\translatable\PaymentMethodBankTransferSK\PaymentMethodBankTransferEN}
\def\IssueDate{\translatable\IssueDateSK\IssueDateEN}
\def\DeliveryDate{\translatable\DeliveryDateSK\DeliveryDateEN}
\def\DueDate{\translatablebf\DueDateSK\DueDateEN}
\def\VariableSymbol{\translatable\VariableSymbolSK\VariableSymbolEN}
\def\Notes{\translatablebf\NotesSK\NotesEN}
\def\Subject{\translatablebf\SubjectSK\SubjectEN}
\def\Amount{\translatablebf\AmountSK\AmountEN}
\def\Unit{\translatablebf\UnitSK\UnitEN}
\def\UnitPrice{\translatablebf\UnitPriceSK\UnitPriceEN}
\def\TotalPrice{\translatablebf\TotalPriceSK\TotalPriceEN}
\def\TotalAmount{\translatable\TotalAmountSK\TotalAmountEN}
\def\IssuedBy{\translatable\IssuedBySK\IssuedByEN}
\def\AdvancesPaid{\translatable\AdvancesPaidSK\AdvancesPaidEN}
\def\TotalDue{\translatable\TotalDueSK\TotalDueEN}

\begin{document}
\footnotesize

\pagestyle{empty}

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

% INVOICE HEADING
&&& \\
\multicolumn{4}{l}{\large\Invoice: \hfill {{invoice.number}}} \\
&&& \\ \hline
\multicolumn{2}{X|}{} & \multicolumn{2}{X}{} \\
\multicolumn{2}{l|}{\Supplier:} & \multicolumn{2}{X}{\Client:} \\
\multicolumn{2}{X|}{} & \multicolumn{2}{X}{} \\

% ISSUER & CUSTOMER
\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}{} \\
    % ISSUER
    \multicolumn{2}{l|}{IČO: {{issuer.ico}}} &
        \multicolumn{2}{l}{ {{if customer.icdph}}IČO: \hspace{0.3cm}{{customer.ico}}{{endif}} } \\
    % CUSTOMER
    \multicolumn{2}{l|}{DIČ: {{issuer.dic}}} &
        \multicolumn{2}{l}{ {{if customer.icdph}}DIČ: \hspace{0.3cm}{{customer.dic}}{{endif}} } \\
{{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|}{\PaymentTerms:} & & \\
\PaymentMethod: & \multicolumn{1}{l|}{
    {{if invoice.payment == "cash"}}
    \PaymentMethodCash
    {{else}}
    \PaymentMethodBankTransfer
    {{endif}} } & & \\
IBAN: & \multicolumn{1}{l|}{ {{issuer.iban}} } & \IssueDate: & \multicolumn{1}{r}{ {{invoice.issued.strftime("%d.%m.%Y")}}} \\
SWIFT/BIC: & \multicolumn{1}{l|}{ {{issuer.swift}} } & \multicolumn{2}{l}{\DeliveryDate: \hfill {{invoice.delivered.strftime("%d.%m.%Y")}}} \\
\VariableSymbol: & \multicolumn{1}{l|}{ {{invoice.number}}} & \multicolumn{2}{l}{\large\DueDate: \hfill {{invoice.due.strftime("%d.%m.%Y")}}} \\
% COMMENTS
{{if invoice.notes}}
\multicolumn{2}{X|}{} & \multicolumn{2}{X}{} \\ \hline
& & & \\
\Notes: & & & \\[1em]
{{for note in invoice.notes}}
\multicolumn{4}{l}{\large {{note}}} \\
{{endfor}}
{{endif}}

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

&&& \\

% ITEM(s) HEADING
{{if invoice.itemheading}}
{{for heading in invoice.itemheading}}
\multicolumn{4}{l}{ {{heading}} } \\
{{endfor}}
&&& \\
{{endif}}

% ITEMS
\multicolumn{4}{X}{%
    \hspace*{-1.35\tabcolsep}
    \begin{tabu} to \textwidth {X[5,l]X[1.5,r]X[1,r]X[1.8,r]X[2.0,r]}
            %>{\hsize=2.5\hsize}X[l]%
            %>{\hsize=0.5\hsize}X[r]%
            %>{\hsize=0.5\hsize}X[r]%
            %>{\hsize=1.0\hsize}X[r]%
            %>{\hsize=1.0\hsize}X[r]}
        \Subject & \Amount & \Unit & \UnitPrice & \TotalPrice \\
        {{for item in invoice.items}}
        {{item[0]}} & {{decimal(item[1])}} & {{item[2]}} & {{eur(item[3])}} & {{eur(item[1] * item[3])}} \\
        {{endfor}}
    \end{tabu}
} \\

&&& \\
\hline
\multicolumn{4}{r}{} \\
\end{tabularx}
\end{center}

\vfill

% FOOTER
\centering
\begin{tabu} to \textwidth {X[1]|X[0.5,l]|X[0.25,r] }
    \hline
    \IssuedBy: \quad {{issuer.name}} & \TotalAmount: & {{eur(invoice.sum)}} \\ \cline{2-3}
    \multirow{2}{*}{\hspace*{2.7cm}\includegraphics[scale=0.2]{../signature.jpg} } & \AdvancesPaid: & {{eur(invoice.advance)}} \\ \cline{2-3}
    && \\
    & \multirow{-2}{*}{\TotalDue:} & \multirow{-2}{*}{ \bf \large {{eur(invoice.topay)}}\phantom} \\
\end{tabu}

\end{document}