Residency & Expat Life

US Tax Basics for Newcomers and Immigrants

A newcomer’s guide to US taxes, understanding the multi-level system, tax residency and who must file, taxpayer identification numbers, how income tax and

Reviewed by the GetInfoUs research teamLast reviewed: 2026-06Editorial policy

Illustration of US tax forms, a calculator and a dollar coin

Understanding taxes in the United States

Taxes are an unavoidable part of life in the United States, and for newcomers the system can seem complicated because taxes are charged at more than one level. You may encounter federal income tax, state income tax in many states, and various local and other taxes, alongside payroll taxes that fund social programs. The most important concept to grasp early is that the US generally taxes based on your residency status for tax purposes and, for some, worldwide income, and that the responsibility to report and file falls on you as the taxpayer. Employers typically withhold tax from your paycheck throughout the year, and you then file an annual tax return to reconcile what you owe with what was withheld, potentially receiving a refund or owing a balance. Understanding the basic structure, who taxes you, on what, and your duty to file, is the foundation. This guide explains the essentials newcomers need to manage their US taxes responsibly and avoid common problems.

Tax residency and who must file

A key early question for newcomers is your tax residency status, because it determines how you are taxed. The US tax system distinguishes between residents and non-residents for tax purposes, and this is not the same as your immigration status. Your tax residency generally depends on factors such as your immigration category and how much time you spend physically present in the US, assessed under specific tests. Residents for tax purposes are generally taxed on their worldwide income, while non-residents are typically taxed only on US-source income, and the forms and rules differ. Because the determination can be nuanced, especially in your first year, it is important to figure out your status correctly, as it affects what income you report and which return you file. Most people who earn income in the US and meet the filing thresholds must file an annual federal tax return, and many must also file a state return. Determining your residency status accurately is the essential first step to filing correctly.

Taxpayer identification numbers

To work, file taxes and be identified in the US tax system, you need a taxpayer identification number. Most people who are authorised to work obtain a Social Security Number, which is used for employment and tax reporting and is one of the first things many newcomers arrange after arrival. Those who are not eligible for a Social Security Number but still have a US tax filing obligation, for example certain dependents or individuals with US income but without work authorisation, may need to apply for an Individual Taxpayer Identification Number instead, which serves tax purposes only. Having the correct identification number is essential, because it is how your income, withholding and tax filings are tracked. Employers will ask for your number when you start work, and you will use it on your tax returns. Sorting out the appropriate identification number early prevents delays and complications when it comes time to be paid and to file, so it should be a priority among your first administrative steps.

How income tax and withholding work

The US income tax system is progressive, meaning higher portions of income are taxed at higher rates through a series of brackets, so not all of your income is taxed at the same rate. When you start a job, you typically complete paperwork that tells your employer how much tax to withhold from each paycheck, and getting this roughly right helps you avoid a large bill or an excessive refund later. Throughout the year, your employer withholds income tax as well as payroll taxes for social programs, and reports your earnings. After the tax year ends, you receive statements summarising your income and the tax withheld, which you use to prepare your return. Your final tax depends on your income, your filing status, and any deductions or credits you qualify for, which can reduce what you owe. If too much was withheld, you receive a refund; if too little, you owe the difference. Understanding this cycle helps newcomers plan and avoid surprises.

Filing your tax return

Filing an annual tax return is how you report your income and settle your tax for the year, and it is a legal obligation for most people who meet the filing requirements. There is an annual deadline by which federal returns are generally due, and many states require a return as well. To file, you gather your income statements and records of any deductions or credits, determine your filing status, and complete the appropriate forms, either yourself, using tax software, or with the help of a qualified tax professional. Newcomers, especially in their first year or with income from more than one country, often benefit from professional help to get residency status and reporting right. Filing accurately and on time matters: late or incorrect filing can lead to penalties and interest. Keep copies of your returns and supporting documents. If you cannot pay in full, it is generally better to file on time and arrange payment than not to file at all, since failing to file carries its own consequences.

Tips for managing your US taxes

Managing US taxes well comes down to organisation and not leaving things to the last minute. From the start, sort out the correct taxpayer identification number and determine your tax residency status, seeking qualified advice if your situation is complex or it is your first year. Keep careful records throughout the year: pay statements, income documents, and receipts for anything that might be deductible. When you start a job, set your withholding thoughtfully so you are not surprised at filing time. Be aware that you may need to file both federal and state returns, and note the annual deadline well in advance. Consider using reputable tax software or a qualified professional, particularly if you have foreign income or assets, since reporting rules for these can be complex and mistakes costly. File on time even if you cannot pay in full, and keep copies of everything you submit. By staying organised, understanding your obligations and seeking help when needed, newcomers can handle US taxes confidently and avoid unnecessary penalties.

Frequently asked questions

Who has to file taxes in the United States?+

Most people who earn income in the US and meet the filing thresholds must file an annual federal tax return, and many must also file a state return. Your obligations depend on your income, filing status and tax residency. Even some newcomers with US income but limited time in the country may have filing duties, so it is important to check your situation.

What is the difference between a resident and non-resident for tax purposes?+

Tax residency is not the same as immigration status. It generally depends on your immigration category and time physically present in the US, assessed under specific tests. Residents for tax purposes are generally taxed on worldwide income, while non-residents are typically taxed only on US-source income, with different forms and rules.

Do I need a Social Security Number to work and pay taxes?+

Most people authorised to work obtain a Social Security Number, used for employment and tax reporting. Those not eligible for one but with a US tax filing obligation may need an Individual Taxpayer Identification Number instead, which serves tax purposes only. Sorting out the correct number early prevents delays when you are paid and when you file.

How does tax withholding from my paycheck work?+

When you start a job, you complete paperwork telling your employer how much tax to withhold from each paycheck. Throughout the year your employer withholds income and payroll taxes and reports your earnings. After year-end you file a return to reconcile what you owe with what was withheld, receiving a refund if too much was withheld or owing the difference if too little.

What happens if I file late or cannot pay?+

Late or incorrect filing can lead to penalties and interest. If you cannot pay in full, it is generally better to file on time and arrange payment than not to file at all, since failing to file carries its own consequences. Keeping good records and noting the annual deadline in advance helps you avoid these problems.