Sales receipts reference number being overwritten with sales invoice number. Even when I type in alphabet. Is anybody else having this problem?

Does the receipt reference number change the moment you type, when you save, or after reopening the transaction? In any case, you need to check the Custom Transaction Numbers section to see whether it's turned on.

This is because all sales forms share a single transaction sequence by default. Here's how to check:

1. Go to Settings.
2. Select Account and Settings.
3. Choose the Sales tab, go to the Sales form content section, and make sure the Custom transaction numbers field is enabled.

If it's not switched on, you will need to open a new sales receipt, type the desired number/letter sequence in the Number field, and click Save.

If this feature is already on, you can create a custom field instead, as QuickBooks Online may try to pull the sales receipt back into the invoice numerical sequence every time.

Additionally, make sure to leave the Receipt No. field numeric so QuickBooks can auto-sequence quietly in the background.

Use the Reference No. or Memo fields, or the Custom Field specifically named "Receipt ID," to input your alphanumeric tracking codes. These fields will never be overwritten by invoice sequences and will map perfectly to your customer forms.

Another common culprit for historical numbers getting rewritten is a third-party application or connector.

If no third-party applications are involved, you can open the Audit Log section and filter by the affected transaction dates to see if a system edit touched those receipts.

Feel free to return here if you have any additional questions.