Do we need vat receipts or just itemised proof of purchase for non vat registered self-employed?

Hi there, @wholehorsehoofca.

If your business is not VAT-registered, there's no need to enter the VAT amount on the sales receipts or on your purchases since it can't be charged nor claimed. 

However, if you've turned on the VAT settings, you'll just have to choose No VAT on the VAT settings or transactions so that it will not be recorded.

By the time your business will convert to VAT-registered, you can check out this reference from HMRC: VAT: detailed information.

Please don't hesitate if you have other concerns or questions. I'd be happy to help you further. Take care and have a beautiful day.