Hello there, Ahlcllc.

QuickBooks automatically assigns numbers to your transactions. If you've manually changed the estimate number, our software will auto-populate the next number in sequence when you create a new one. For now, we're unable to turn off this feature.

I suggest sending this idea directly to our product engineers. We're actively gathering feedback from our customers to continuously improve our software and provide you with the best features possible. Just click Help, go to Send Feedback Online, then choose Product Suggestion. 

You're always welcome to post in the Community if you have other concerns.