Before you start

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

Step-by-step

1
Check your tax code in your first payslip
PAYE deducts tax at source and a wrong code means wrong deductions for months. Your code should not begin with an S — that is the Scottish prefix, occasionally applied in error when payroll is run from elsewhere.
Via employerWho: YouFirst payslip
2
Understand the three English bands
A personal allowance, then Basic, Higher from £50,270, and Additional from £125,140. The allowance and thresholds have been frozen for several years, which pulls more people into higher bands each year as wages rise even with no rate change.
OnlineWho: You
3
Model the 60% band if you earn above £100,000
The personal allowance is withdrawn at £1 for every £2 earned above £100,000, producing an effective marginal rate of about 60% between £100,000 and £125,140. Pension salary sacrifice is the standard response. Bristol's senior aerospace, chip design and finance roles sit squarely in this range.
OnlineWho: You
4
Check whether you need to file Self Assessment
Most employees do not — PAYE handles it. You do if you are self-employed, have significant untaxed income, or earn above a threshold. The deadline for online returns is 31 January following the tax year.
OnlineWho: You
5
Understand your residence position in year one
The Statutory Residence Test determines UK tax residence by days present and connecting factors. If you have foreign income or assets, take advice in your first year — the UK abolished the old non-domiciled regime and replaced it with a residence-based system, and the transitional rules are complex.
In personWho: You
6
Budget National Insurance separately
NI is charged on earnings in addition to income tax, at UK-wide rates, with a separate employer contribution you never see. Comparisons that look only at income tax understate what actually comes out of a UK salary.
OnlineWho: You

Documents you’ll need

National Insurance number
P60 — the annual summary from your employer
P45, if you change jobs during the year
Records of foreign income and overseas accounts
Government Gateway credentials, for Self Assessment

Things most newcomers don’t know

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The personal allowance is withdrawn at £1 for every £2 of income above £100,000, so each extra pound in that range is effectively taxed at around 60%. A rise from £99,000 to £110,000 delivers far less than it appears to. Salary sacrifice into a pension is the standard remedy, and it is worth modelling before accepting an offer in that range — which a lot of Bristol's chip design and aerospace roles are.

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

Bristol salaries do not fully compensate for Bristol housing costs.

Rents here are the highest of any English city outside London and the South East, and Council Tax bands run high, but pay for most roles is benchmarked regionally rather than against London. The result is that take-home relative to housing cost is worse in Bristol than in Manchester or Leeds for the same job. Model the whole package rather than the salary — the gap is real and it surprises people who moved here expecting to save money after leaving London.

Source: community-reported

Frozen thresholds are a tax rise nobody votes for.

The personal allowance and the higher-rate threshold have been held flat for several years while wages rose. Each year more people cross into higher bands without any rate changing — the mechanism is called fiscal drag and it is why your take-home percentage falls slightly each April even without a promotion.

Source: HMRC

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

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

Source: HMRC

Common mistakes to avoid

Accepting a salary between £100,000 and £125,140 without modelling the 60% effective band.
Assuming Bristol is a cheap alternative to London without modelling rent and Council Tax together.
Not checking that your PAYE code is right, and that it does not carry a Scottish S prefix.
Counting your tax year as January to December rather than 6 April to 5 April.
Ignoring National Insurance when estimating take-home pay.

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