Before you start

A valid Iqama (residence permit) — the basis of your legal employment and GOSI registration
An employment contract, ideally registered in the Ministry of Human Resources' Qiwa system, confirming your gross salary
A local bank account so salary is paid under the Wage Protection System (see the banking guide)
Awareness of your home-country tax rules if you are a citizen of a country that taxes worldwide income (notably the US)

Step-by-step

1
Confirm there is no personal income tax to register for
Saudi Arabia imposes no personal income tax on employment income. There is no PAYE-style income-tax deduction and no personal income-tax return for employees — you never register with ZATCA as a salaried worker because there is nothing to file.
OnlineWho: You (nothing to action)n/a — no filing existsSAR 0 (no personal income tax)
2
Let your employer register you with GOSI
Your employer registers you with the General Organization for Social Insurance (GOSI) when you start. For non-Saudi employees this is a 2% occupational-hazard contribution — paid entirely by the employer, with nothing deducted from your salary. It covers work injuries, not a pension: expats do not pay into and do not draw the Saudi pension. (Saudi nationals are a different story — see the insights.)
Via employerWho: Employer registers; GOSI administersAt onboarding; ongoing monthlySAR 0 to you (employer pays 2%)
3
Budget for 15% VAT on your spending
What you do not pay in income tax, you partly meet at the till. ZATCA levies a 15% standard VAT on most goods and services — tripled from 5% in July 2020 and still among the highest rates in the Gulf. It is already baked into shop and restaurant prices. Residential home rent is exempt, and some essentials are zero-rated, but day-to-day costs carry the full 15%.
OnlineWho: You (as a consumer)Ongoing, on purchases15% VAT embedded in prices
4
Check whether your home country still taxes you
Tax-free in Riyadh is not always tax-free worldwide. US citizens and green-card holders must file a US return on worldwide income wherever they live — the Foreign Earned Income Exclusion and foreign tax credits often cut the bill to little or nothing, but the filing is mandatory, and an FBAR is required if your foreign accounts top USD 10,000. Other nationals should check their own residency and remittance rules before assuming zero.
OnlineWho: You (consider a cross-border tax adviser)Aligned to your home-country deadlinesVaries; adviser fees if used

Documents you’ll need

Iqama (residence permit) — underpins your employment and GOSI record
Employment contract / Qiwa-registered offer confirming gross salary
Monthly payslips and a salary certificate from your employer (for home-country or treaty use)
Home-country tax forms, only if you have an obligation there (e.g. US Form 1040, FBAR)

Things most newcomers don’t know

Your salary genuinely is income-tax-free — and as an expat, GOSI does not touch it either.

Saudi Arabia has no personal income tax, so there is no income-tax line on your payslip. The frequent worry — that GOSI will quietly eat your pay like social security elsewhere — is misplaced for non-Saudis: your only GOSI cost is a 2% occupational-hazard premium your employer pays, with zero employee deduction. The gross on your offer is broadly what lands.

Source: PwC Worldwide Tax Summaries / GOSI

GOSI hits Saudi nationals far harder than expats — do not read their deductions as yours.

A Saudi colleague pays roughly 9.75% of salary into GOSI (pension plus SANED unemployment), with the employer adding more — around 21.5% combined. As a non-Saudi you are outside that pension scheme entirely. Salary calculators built for Saudis can wildly overstate what comes off an expat's pay.

Source: PwC Worldwide Tax Summaries

Zero income tax, but a 15% VAT — one of the steepest in the Gulf.

Saudi Arabia tripled VAT from 5% to 15% in July 2020 and kept it there, versus 5% in the UAE and Qatar. It will not show on your payslip, but it lifts the real cost of living noticeably. Newcomers comparing Gulf 'tax-free' packages often miss that Riyadh claws back more through consumption than its neighbours.

Source: ZATCA / PwC Worldwide Tax Summaries

There is no personal tax return to file in Saudi Arabia — but keep your own records.

As an employee you never register with ZATCA or submit a personal return. The flip side is that no authority issues you a tax statement, so you must keep payslips and a salary certificate yourself for any home-country filing, a tax-residency certificate to claim treaty benefits, or mortgage and visa paperwork.

Source: PwC Worldwide Tax Summaries / ZATCA

Common mistakes to avoid

Assuming tax-free in Saudi Arabia means tax-free worldwide — US citizens (and some others) still owe a home filing, plus an FBAR if foreign accounts exceed USD 10,000.
Expecting big GOSI/pension deductions from your pay: as a non-Saudi you contribute nothing, and you do not accrue a Saudi pension to take home.
Forgetting the 15% VAT when budgeting — it is invisible on payslips but inflates nearly every purchase, unlike the 5% expats may know from the UAE or Qatar.
Trusting a Saudi-national salary calculator (showing ~10% GOSI off the employee) to estimate an expat's net pay — the schemes are different.