We have 2 companies on QBCompany A's Income of £2k & £3k was input on to Company B in error£5k physically transferred - Suggestions please for journals/ transactions?

If I understand this

A earned 5K, but the deposit was made to B

B writes a check/EFT to A and use the same account that the deposit was posted to and A deposits the check as income

Journal entries should be the exception when using QB, they often do not work as you think they should, and when you use inventory type items they never work for inventory. It is much better to use the forms on the home page the way QB is designed to be used. Journal entries also bypass accrual/cash reporting, and will not show on many reports.

But if you insist, and the deposit was recorded as income in B
debit B income
Credit bank