Hi, I have been advised I need to add my company number to my invoices, how do I add this detail to my invoices going forward without having to type it on every one ?

Hello, keychaineotservi. 

Thank you for reaching out to the Community, You can add details to your invoices by adding custom fields, headers or footers to the invoice. 

Let me show you how:

1. Click on the Gear icon, then Custom Form Styles.
2. Choose New style or choose the type of transaction you want to customize.
3. Press on Content.
4. Click the boxes under Invoices and other sales forms or Add payment details and footer to enter any information.
5. Tap Preview PDF to view the changes you made before saving them.
6. Hit Done. 

For more insights, please refer to this article: Adding details to your invoices. Other option is import your custom form style. 

Please feel free to get in touch with me here for any additional questions, I always have your back. Keep safe always!