Can I implement a bespoke product reference number system ?

Thank you for visiting the Community, @accounts-carehom. I'm very eager to share some workarounds about your concern.

You can use the Custom transaction numbers feature to set your own numbering preference in QuickBooks Online. Here’s how:

1. Go to the Gear Icon, then click Account and Settings.
2. Select Sales, then click the pencil icon.
3. Tick the box next to Custom transaction numbers.
4. Click Save and Done.

You can also use the SKU feature in QBO to help track your inventory per item. Here are the steps to turn on SKU feature:

1. Go to the Gear Icon, then click Account and Settings.
2. Select Sales, then click the pencil icon.
3. Tick the box next to Show SKU column.
4. Click Save and Done.

Furthermore, you can refer to this link if you want to add inventory products in QuickBooks Online.

Please let me know if you have any questions about QuickBooks. I'll be right here to help. Have a great day!