I am trying to add a payment recieved from the HMRC (CIS Tax rebate) - could anyone advice how I would categorise this?

Good day, paula_kemp.

I'll share with you the steps on how you can the add rebate in QBSE. Here's how:

1. Go to the Transactions tab and click Add transaction.
2. Enter all the required detail such as the date of the transaction, description, and amount.
3. Click Select a category. I would recommend reaching to your CPA or a tax professional to verify what category to use for this rebate. 
4. Click Save.

Let me also share these articles about categories for more reference:

• About SA103F Categories
• Custom Categories In QuickBooks Self-Employed

Let me know if you need anything else.