Before you start

A National Tax Number via the FBR's IRIS portal
A day count for the tax year
Salary certificates or accreditation documents and any foreign income records
A Pakistani bank account

Step-by-step

1
Count days against a 1 July–30 June year
183 days or more of presence in the tax year makes you a resident individual taxed on worldwide income. The year ends on 30 June, so a spring arrival crosses the line differently from what a calendar-year assumption suggests. Count carefully in the first and last years.
OnlineWho: YouOn arrival
2
Establish whether an accreditation changes your position
Staff of accredited international organisations and diplomatic missions may be treated differently under host-country agreements. This is not uniform across organisations and it determines whether you file at all. Get it in writing from your organisation's administration in month one — not from a bank and not from a general adviser.
Via employerWho: YouMonth 1
3
Register for an NTN on IRIS
Pakistani individuals use the CNIC as their tax number; foreign nationals register separately on the FBR's IRIS portal. Banks want it and it is the precondition for filer status.
OnlineWho: You
4
File on time, every year
Filing is what places you on the Active Taxpayers List; registering is not. The list rebuilds weekly and late filers are admitted only on payment of a surcharge. Salary tax withheld at source does not remove the obligation.
OnlineWho: YouAnnually, by the FBR due date
5
Note that services tax here is federal, not provincial
Sales tax on services is levied provincially across Pakistan, but the Islamabad Capital Territory has no provincial revenue authority — the equivalent administration for ICT is federal. A consultant registered with the Punjab Revenue Authority is not thereby registered for Islamabad, and vice versa. Confirm with the FBR which registration your activity requires.
OnlineWho: You
6
Resolve the treaty position on any foreign income in year one
Pakistan has a wide double taxation treaty network, and the FBR's head office being in this city makes formal queries genuinely easier to pursue. If you are resident here and taxed elsewhere on the same income, get advice once rather than guessing annually.
OnlineWho: You

Documents you’ll need

NTN and IRIS login
Salary certificate and withholding statements, or accreditation documents
Bank statements
Records of foreign income and foreign tax paid
Property documents, where relevant

Things most newcomers don’t know

Islamabad has no provincial revenue authority, and that is not a technicality.

Every Pakistani province levies its own sales tax on services through its own authority — the Punjab Revenue Authority, the Sindh Revenue Board, and equivalents in KP and Balochistan. The Islamabad Capital Territory has none, so the equivalent administration is federal. A consultant who moves from Lahore to Islamabad does not simply update an address; the registration regime changes. Advisers frequently specialise by province, and 'we handle Pakistan' should always be tested with 'do you handle ICT?'.

Source: Federal Board of Revenue; provincial revenue authorities

The residency test is 183 days in a year ending 30 June, and residence brings worldwide income into charge.

A resident individual is one present in Pakistan for 183 days or more in the tax year, which runs July to June rather than as a calendar year. Crossing it means Pakistan taxes worldwide income rather than only Pakistan-source income. Arrivals in the first quarter of a calendar year cross the threshold in a way that surprises them, and the same arithmetic runs in reverse in a departure year.

Source: Federal Board of Revenue

Accredited international-organisation staff need their own answer, in writing, from their own employer.

Pakistan's host-country agreements with international organisations are not uniform, and the tax treatment of an accredited post can differ substantially from an ordinary employment. Bank staff do not know. General tax advisers frequently do not know. Your organisation's administration does, and the answer determines whether you file, whether you appear on the Active Taxpayers List, and how your salary is treated. Islamabad is the city where this question arises most often and is most often answered by guesswork.

Source: community-reported

Filer status is a transactional discount, and it lapses.

The Active Taxpayers List determines withholding on property purchases, vehicle registration, dividends and certain banking activity, and the gap between filer and non-filer rates is large enough to matter on any significant transaction. An NTN alone does not put you on it; filing by the due date does, and a late filer pays a surcharge to be admitted. Because the list is rebuilt weekly, a missed year drops you off it. In Islamabad's property market this single mechanism is worth more than any deduction available.

Source: Federal Board of Revenue