Hi,

Refer the blog:

https://www.cybrosys.com/blog/how-to-create-custom-header-and-footer-for-website-in-odoo-16

Hope it helps

He is not asking for Invoices or Quotations, he wan't to modify the header of the website. I personally want to custom the cart and it is not something easy to do at all...

To customize the header and footer in Odoo (for reports like invoices, quotations, etc.), follow these steps:

Step-by-Step:

1. Activate Developer Mode
   Go to Settings → Activate Developer Mode.
2. Go to Report Templates
   Navigate to Settings → Technical → Views.
3. Search for the template
   Look for:
   • external_layout_standard (for standard header/footer)
   • Or external_layout if you're using a customized theme
4. Edit the XML
   Modify the header/footer section using QWeb (XML) tags.
   Example for adding a phone number in the footer:

   xml
   CopyEdit
   <t t-name="your_custom_footer">
       <div>Phone: <span t-field="company.phone"/></div>
   </t>
   

5. Save and Test
   • Go to Invoices or Quotations
   • Print a report to check changes

If you're using Studio, you can also customize headers/footers visually in Reporting → Custom Report Layouts.

Let me know if you need the XML sample for specific changes (like logo, address, or styling).

At Wan Buffer Services, we often help startups and enterprises go through this process to avoid common mistakes and get the best ERP fit — especially with solutions like Odoo.