QB Issue Resolution:

Great Question! Let me show you where you can do that at:

Click on the Gear Icon> under Settings> Click on Settings> Click Company Settings> Sales> Sales form content> Custom transaction numbers> this is where you would be able to turn on this feature.

Resolution for Issue 'I want to change the invoice numbers moving forward. They are starting at 1000 and the only way to change them is each time I create an invoice.' available: Yes (Solved).
Source: Intuit Community forum.

I want to change the invoice numbers moving forward. They are starting at 1000 and the only way to change them is each time I create an invoice.: this issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the issue yourself by looking for a resolution described below. If it is a complex issue or you are unable to solve the issue, you may contact us by clicking here or by using other support options.

Support for Invoice
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Error Recovery for Invoice [Canada]
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