Resident company
In one sentenceA company considered resident in the Kingdom for income tax purposes because it is established under its laws or because its central management is here, so its income is subject to the rules for residents.
Simply put
Tax residency is different from nationality: a Saudi company owned by foreigners is tax resident, and a foreign company may become resident if it is centrally managed from the Kingdom.
A resident files an annual return on its income, and must deduct withholding tax when it pays non-residents.
Example
A limited liability company registered in the Kingdom owned by a Saudi partner and a foreign partner: it is a resident business, paying Zakat on the Saudi partner's share and income tax on the foreign partner's share.
Don't confuse it with
Non-residentA resident is taxed on its income through an annual return, while a non-resident is usually taxed through withholding on what is paid to it.