The cheque numbers are out of sequence. How do I change that?

Hi there, 

Glad to have you connect with us here in the Community. QuickBooks is equipped with the tools you need in order to streamline your accounting. I'll be glad to provide the steps you need in order to prevent the system from automatically assigning custom invoice numbers. 

Based on the details you've shared above, I gather you have the Custom transactions numbers enabled on your account. This feature allows you to add a custom transaction number to form and the system will maintain the number sequence automatically for you.  You'd need to turn this feature off in order to achieve the goal you've mentioned above. Here's how: 

1. Navigate to Settings ⚙ and select Account and settings.
2. Click Sales.
3. In Sales form content, select Edit ✎.
4. Turn Custom transaction numbers off.
5. Select Save, then select Done.

There you go. You now know how to turn off the Custom Transactions number feature on your account. Give this a try and let me know how you make out. I'll be one message away in case you need anything else.