Hello there, @xyz9.

As mentioned by QuickBooks Team and other users, the transaction ID is unique that cannot be changed or manipulated. The Transactions ID is a system-generated number that cannot be viewed when creating a transaction inside the software.

I can see that this feature plays an important part in QuickBooks Online users to smoothly manage transactions and other data. You'll want to send this product suggestion to our Product Development team. Here's how:

1. Go to the Gear icon.
2. Select Feedback under Profile.
3. Enter your suggestion. Then, click Next.

While the transaction number you used to manage with your sales transaction can be manually changed, here's how:
 

1. Go to the Gear icon.
2. Under Your Company, select Accounts and Settings.
3. On the Sales page, click Sales form content.
4. Select the checkbox for Custom transactions numbers to turn it on. 
5. Click on Save and then Done.

If you run sales or any reports soon, you can use these articles to manage them well:
 

• Customize reports
• Memorize reports

Visit again if you need anything else, xyz9. Take care and have a good one.