The penalty for late filing is a fee of 1 percent of the unpaid tax for each thirty days delay from the due date RIYADH: Saudi withholding tax payers must submit their May returns by June 10. The Saudi Zakat, Tax and Customs Authority urged business tax payers on its official website to submit their returns quickly to avoid a fine. The penalty for late filing is a fee of 1 percent of the unpaid tax for each thirty days delay from the due date. Taxpayers wishing to obtain more information regarding withholding tax can contact the Authority by phone 24 hours-a-day, seven days-a-week. Help is also available through the “Ask Zakat and Tax” account on Twitter, or email, or through instant chats via the website, the Authority said. Withholding tax is deducted from the total income of a non-resident establishment in Saudi Arabia, in return for services it provides inside the Kingdom.