Could you use a helping hand from the Rhino accounts app?
If you’d like some help with your accounts and need advice on submitting tax returns, try the HMRC-recommended app Rhino.
Must I retain paper receipts for my expenses?
No. HMRC no longer requires you to present paper receipts. They only need to have a copy that is readable. A digital copy is fine and is more reliable than a till receipt that may fade over time. Just use Rhino on your phone to photograph receipts as you get them. https://www.gov.uk/guidance/software-for-sending-income-tax-updates
How about invoices? Should I keep paper versions of those?