Here is the thing. You shouldn’t be using tags such as
<body> etc. this is because Manager UI is already HTML document and your HTML code is injected into existing HTML markup.
New version will actually sanitize HTML code so it’s not possible to use those tags anymore. So you should insert only:
<H4>TERMS & CONDITIONS</H4>
<ul>1. Cheques are to be made payable to Richard XXXXX.</ul>
<ul> *Note: Charges may be levied on uncleared cheques.</ul>
<ul>2. Direct payment can be made into the following account:</ul>
<ul> Suncorp / BSB No: XXX - XXX</ul>
<ul> Account No: XXXXXXXX</ul>
<ul> Account Name: XXXXXXX XXXXXXX</ul>
<ul> *Note: Please use invoice reference number (INXXXX) as payment reference number when using this method.</ul>
<ul>3. Goods sold are not returnable or refundable. They are covered by manufacturer warranty.</ul>
<ul>4. Having been issued with this invoice implies that work has been carried out and that the above mentioned person/company agree to the terms and conditions of this invoice.</ul>
<ul>5. The customer will be liable for all costs incurred by Richard XXXXXX T/A Company Name for collection of outstanding monies for the supply of products, consultation or work carried out (including Legal, Debt Collection, Bank Charges, Interest on Over Due accounts).</ul>
But this HTML code is still not right. You should look into tags such as
<ol> to see how to make lists in HTML.