How should the installation fee be accounted for?

If there is, it will be included in the account of "main business income", if not, it will be included in the account of "other business income".

If the installation costs have not yet been received, but have been invoiced in the tax office,

Borrow: Accounts Receivable - XX Company? XXXX yuan

credit: major business income XXXX yuan

or

borrow: other receivables-XX company XXXX yuan

credit: other business income XXXX yuan