Let me classify a payment as a transfer between accounts

I'm trying to classify a £2,400 payment that comes in every month as a transfer between accounts, but there's no way to do it. The account it lands in is a joint account, so the money isn't income, it's a transfer. Expected: to be able to label an incoming payment as a transfer between accounts so it stops being counted as salary/income. What happens: there is no transfer label available, so it stays detected as a primary salary and skews the income figures.