Before you start

A National Insurance number
PAYE registration through your employer
A Government Gateway account, if you ever need Self Assessment
Records of foreign income and overseas accounts

Step-by-step

1
Check the tax code on your first payslip
PAYE deducts at source, so a wrong code means wrong deductions for months before anyone notices. Your code should not begin with an S — that is the Scottish prefix — or a C, which is the Welsh one. A code ending in W1 or M1 is an emergency code, which is common on a first UK payslip and should be corrected once HMRC has your details.
Via employerWho: YouFirst payslip
2
Watch your code if you have two jobs or work through an agency
Second and agency employments are frequently put on a BR or 0T code, which taxes every pound with no personal allowance. That is sometimes correct and often not, particularly if the first job does not use the whole allowance. Check your Personal Tax Account, tell HMRC how you want the allowance split, and reclaim any over-deduction — this is the single most common payroll error in a town with this much shift work.
OnlineWho: You
3
Learn the three English bands
A personal allowance, then Basic, Higher from £50,270 and Additional from £125,140. The thresholds have been frozen for several years, which quietly pulls more people into higher bands each year as wages rise — overtime-heavy roles cross them more often than base salaries suggest.
OnlineWho: You
4
Understand the 60% trap above £100,000
The personal allowance is withdrawn by £1 for every £2 earned above £100,000, giving an effective marginal rate of about 60% between £100,000 and £125,140. Pension salary sacrifice is the standard response. It is the most consequential quirk in the English system and it is signposted nowhere.
OnlineWho: You
5
Check whether you actually need to file Self Assessment
Most employees never do — PAYE handles it. You must register if you are self-employed, have significant untaxed income, or meet one of HMRC's listed triggers. Online returns are due by 31 January following the 5 April year end.
OnlineWho: You
6
Settle your residence position in year one
The Statutory Residence Test determines UK tax residence from days present and connecting factors. The UK abolished the old non-domiciled regime and replaced it with a residence-based system, and the transitional rules are genuinely complex. Take advice in the first year if you have foreign income or assets.
In personWho: You

Documents you’ll need

National Insurance number
P60 — the annual summary from your employer
P45, if you change employer during the year
Payslips for every concurrent employment
Government Gateway credentials, for your Personal Tax Account and Self Assessment

Things most newcomers don’t know

Two jobs is where PAYE goes wrong, and this is a two-jobs town.

Airport shifts, warehouse work and hospitality frequently mean concurrent employments, and the second one is typically coded BR or 0T — no personal allowance at all. If the first job does not use the whole allowance, you are overpaying every month and nothing flags it. Your Personal Tax Account lets you see every live employment and tell HMRC how to split the allowance, and overpaid tax is reclaimable. Almost nobody arriving from a withholding-tax country knows to look.

Source: GOV.UK — tax codes: if you have more than one job

An emergency code on your first payslip is normal, and leaving it there is not.

A code ending W1, M1 or X taxes each period in isolation, ignoring what you have already earned in the year, and it is applied by default until HMRC has your details. It usually corrects itself once a P45 or a starter checklist lands — but if it does not, you carry the over-deduction until the year end. Check payslip two as well as payslip one.

Source: GOV.UK — tax codes

The 60% band between £100,000 and £125,140 is the biggest hidden rate in the system.

The personal allowance is withdrawn at £1 for every £2 above £100,000, so each extra pound in that range is taxed at the 40% headline rate plus the lost allowance — around 60% in effect. Airline head-office and senior operations salaries reach it. Model it before accepting an offer in that range and look at salary sacrifice.

Source: GOV.UK — income tax rates and personal allowances

The tax year runs 6 April to 5 April, which catches everyone once.

Almost no other country uses these dates. It decides which year your arrival income falls into, when your P60 arrives, and when Self Assessment is due. Newcomers routinely reckon against a calendar year and get their first filing wrong.

Source: HMRC

Common mistakes to avoid

Working two jobs without checking how HMRC has split your personal allowance.
Leaving an emergency W1/M1 code in place after the second payslip.
Not checking the PAYE code for a stray Scottish S or Welsh C prefix.
Accepting a salary between £100,000 and £125,140 without modelling the 60% effective band.
Counting the tax year as January to December rather than 6 April to 5 April.

Some of this may be out of date. Spotted something inaccurate? Help us keep it right for the next newcomer.