I upload photos of documents as attachments using mobile device and attach to the bill. The link to attach existing attachment is gone - it was BELOW the attachment box

I've got the steps so you can upload the documents to your bill, @baystatecharitab.

The stored cache can affect the performance of QuickBooks which can cause unexpected behavior.

To begin, I'd suggest logging in to your QBO account via a private window. This doesn't use the existing cache files, which makes it a good place to determine if there's an issue with the browser. 

Here are the keyboard shortcuts: 

• Safari: Command + Shift + N 
• Google Chrome: CTRL + Shift + N
• Mozilla Firefox or Microsoft Edge: CTRL + Shift + P 

After signing in, verify if the attachment box is there. If yes, let's clear the cache of your browser. This helps remove its stored cache to improve the program's performance.

Otherwise, I'd also recommend using different browsers. They'll provide you with the best and most secure experience with QuickBooks. For more details, see this article: System Requirements For QuickBooks.

Also, you can review the Attachment page if the photos were there. Then try to upload the photos again.

I'll be adding these resources that will help you attach documents to your transactions:

• Attachments in QuickBooks Online
• Upload your receipts and bills to QuickBooks Online

Should you need anything else, let me know by commenting below, I'm always here for you. Have a wonderful day, @baystatecharitab.

Thank you but all those options do not work, I do not want to create any transaction.

I take a photo of correspondence that I receive from a Vendor after bill is paid and attach to the bill.

No transaction, the correspondence is the acknowledgement of their receipt of our check.

We are a non-profit and have to keep these letters for IRS purpose so they are important.

Up until last week we were having no problem and then the link disappeared.

On the bill, there was a line that said attach or see existing files - it would open the attachment list on the right side screen and files were listed.

 I can see the photo of correspondence but there is no way to attach to the bill. Again, I do not want to create any transaction - the transaction is all done - this important correspondence to retain with payment.

I appreciate the steps you've taken, baystatecharitab.

As much as I wanted to check on this, I am unable to do it here since Community is a public forum. I suggest reaching out to our phone support team to have this better checked. they have more tools, like screen-sharing, and determine the root cause of the issue, then troubleshoot it for you.

1. Click the (?) Help icon and choose the Talk to a human option (then type it again when prompted).
2. When asked by the bot, type "link to attach existing bill is gone."
3. Select I still need a human, then proceed with Contact us.
4. Tap Let’s talk then, choose either Get a call or Start messaging. 

 You can also visit our manage vendors page for tips and articles you can refer to for future tasks in QBO.

Feel free to visit the Community for more questions and I'll be happy to answer them for you. I hope you have a great week ahead.