I am trying to edit my invoice but i cannot complete this its saying to contact the help service but my invoice is due tomorrow any ideas how to manage this

Good to see you here, @bentley_warrior-. I acknowledge the significance of editing the invoice and sending it to your customer. I will provide you with some troubleshooting steps to resolve this issue promptly.

The stored cache and cookies in your browser can become corrupted, leading to unusual behaviors such as runtime errors and unresponsive pages. To address this, you can start by accessing your QuickBooks in an incognito or private browser window. You may use these keyboard shortcuts to launch the window:

• Google Chrome: press Ctrl + Shift + N 
• Mozilla Firefox and Microsoft Edge: press Ctrl + Shift + P
• Safari: press Command + Shift + N

Once you're in, you can now edit the invoice. If this works, go back to your regular browser and clear the cache. This will remove the stored cache or cookies to refresh your browser. If not, use another supported browser. It could be that the one you're currently using has a temporary issue with QuickBooks. 

However, if the problem continues, I recommend getting in touch with out Support Team to check and investigate this further securely. For the support's contact information, you can check it here: Contact the QuickBooks Online Customer Support team.

I've added some articles for more details about invoicing in QuickBooks Online:

• Record invoice payments in QuickBooks Online
• Customise invoices, quotes, and sales receipts in QuickBooks Online

Please keep me updated on the results of your attempt to edit an invoice, or if there is anything else I can assist you with regarding QuickBooks. I am here to provide further assistance. Have a great day.