Thanks for jumping into this thread, cyruscontrols.

Let's try a few troubleshooting steps to isolate this issue about changing the word Estimate to Quotation. There are times when a browser's cache becomes full or damaged. When this happens, issues like this can occur.

To start with, let's try logging in to your QBO account using an incognito or private browser. Since this doesn't store data in the cache, it the best place to isolate browser issues.

Kindly use either of the following shortcut keys:
 

• Google Chrome, press CTRL  + Shift + N
• Mozilla Firefox: press CTRL  + Shift + P
• Safari: press Command + Shift + N 

Try performing the steps shared by Catherine_B again. If it works, you may want to clear the browsing history of your regular web browser. This will remove previously-stored browsing data that might have caused the issue. Otherwise, you can try using other supported browsers to be thorough.

For additional reference, you can read through this guide on how to customize invoices, estimates, and sales receipts.

The Community is always open if you have other questions. I'll be around to help. Wishing you a great day ahead!