How do i change the start number of a quote ?

Hello there, @kresin.

You'll have to enable the Custom transaction numbers option and manually change your new quote's number so you can start with a unique number with the said transaction in QuickBooks Online (QBO). I'll guide you on how to do this to help you manage your sales and income transactions accordingly.

To enable the Custom transaction numbers option, here's how:

1. Go to the Gear icon.
2. Select Account and settings.
3. On the Sales tab, enable the Custom transaction numbers option.
4. Click Save and then Done.

Once you're done, go to the + New button and open a new quote (estimate) transaction. From there, manually change or enter your preferred number. Please see the screenshot below for your reference. The next quote you create will automatically assign the unique number in a sequence.

You can refer to this article to learn more about adding specific info to your sales forms in QBO: Customise invoices, quotes, and sales receipts in QuickBooks Online.

Also, you can convert your quotes to invoices so you can bill your customers. You may want to check out this article to learn more about this process and help you manage your sales transactions in QBO: Create and send quotes in QuickBooks Online.

Please feel free to leave a comment below if you have other concerns about managing quotes and sales transactions in QBO. I'm always ready to help. Take care, @kresin.