What does D0 mean on my tax code?

D0 means all income from this source is taxed at 40% (higher rate) with no Personal Allowance. It's used for secondary income sources when the basic-rate band is already filled by a primary income.

When should I request D0?

When your main income exceeds £50,270 (filling the basic-rate band) and you have a second income source that will be entirely in higher rate.

Is D0 better than BR?

It's not 'better' — it depends on your total income. BR (20%) is correct for secondary income within basic rate; D0 (40%) is correct for secondary income in higher rate. The wrong choice means over- or underpayment.

Can I have D0 on my main job?

Generally no — your main job typically uses 1257L (with PA). D0 applies to secondary sources. If HMRC has applied D0 to your main job, contact them to investigate (likely a coding error).

Does D0 apply to pension income?

Yes — second pensions or pension drawdowns commonly use D0 when the main income exhausts basic rate. Pension providers apply the code HMRC issues.

How do I switch from D0 to D1?

Phone HMRC or update via Personal Tax Account when your main income exceeds £125,140 (additional-rate threshold). HMRC may switch automatically based on prior-year data.

Will D0 trigger the 100k taper?

Not at the source — D0 just applies 40%. The PA taper (above £100k) is reconciled at year-end via P800 or SA, often resulting in a balancing payment owed.

Can I split a job's income across BR and D0?

No — each PAYE source has one code at a time. If you straddle bands, HMRC may issue a tailored T-code with bespoke allowance instead.

D0 Tax Code Calculator UK 2025/26 | All Income at 40% Higher

When D0 is the right code in 2025/26

D0 is HMRC's "all-at-40%" code for secondary income sources where the basic-rate band is already exhausted by a primary source. Use cases:

Second job after main job pays £55,000+.
Second pension where main pension or salary is over £50,270.
Director taking salary + dividends where dividend allocation triggers a separate PAYE source.
Multiple part-time roles totalling above the higher-rate threshold.

D0 produces the correct tax outcome when:

Total income across all sources is between £50,270 and £125,140.
The secondary source is entirely within the higher-rate band.

D0 produces wrong outcomes when:

Total income exceeds £125,140 — should use D1 (45%) for the additional-rate portion.
Total income falls below £50,270 — should use BR (20%) instead.

How to request D0 from HMRC

HMRC normally issues D0 automatically based on prior year's reconciliation, but if you start a second job mid-year and expect higher-rate income, request it directly:

Log in to your Personal Tax Account at gov.uk.
Navigate to "Manage your tax codes".
Select the secondary income source.
Request D0 from the dropdown of override codes.
HMRC processes the request within 2-4 weeks.

Alternatively, phone HMRC on 0300 200 3300. Have your NI number, employer details, and expected gross from each source ready.

Why bother: A £15,000/year second job at BR (20%) instead of D0 (40%) results in a £3,000 underpayment at year-end. By requesting D0 upfront, you avoid the lump-sum bill in January (with potential interest charges if late).

Three worked examples (UK 2025/26)

Example 1: £70k main + £10k second job — D0 fits

Aisha earns £70,000 main + £10,000 freelance second. Second on D0.

Calculation: Main 1257L: PA £12,570, basic £37,700 × 20% = £7,540, higher £19,730 × 40% = £7,892. Tax £15,432. Second D0: £10,000 × 40% = £4,000. Total tax £19,432. Correct calculation total £80,000: PA £12,570, basic £37,700 × 20% = £7,540, higher £29,730 × 40% = £11,892. Total £19,432. Match.

Example 2: £140k main + £10k pension — D0 underpays (need D1)

Charles earns £140,000 main + £10,000 personal pension drawdown. If pension on D0:

D0 calculation on pension: £10,000 × 40% = £4,000. Correct rate: 45% × £10,000 = £4,500. Underpayment £500. Should switch to D1.

Example 3: £55k main + £8k second on BR (wrong) vs D0 (correct)

Tom earns £55,000 main + £8,000 second job. Second on BR (incorrect).

BR result: Second £8,000 × 20% = £1,600. D0 correct: £8,000 × 40% = £3,200. Underpayment £1,600 collected at year-end via P800 or SA. Switching to D0 spreads the £3,200 across 12 monthly payslips (£267/month) instead of a January lump sum.

Common mistakes to avoid

Letting HMRC default to BR when total income is clearly in higher rate — proactively request D0.
Forgetting D0 still doesn't trigger the £100k PA taper — additional 60% effective rate not collected at source.
Using D0 when the secondary source is small enough to fit within remaining basic rate — overpays tax.
Confusing D0 with K code — D0 is no allowance + 40%; K is negative allowance + progressive bands.
Failing to switch D0 → D1 when main income crosses £125,140.
Believing D0 is permanent — HMRC reviews and may switch back to BR if circumstances change.

When to use this calculator

Use this calculator any time you start a second income source while your main is in higher rate. Run it before agreeing to freelance gigs, part-time work, or pension drawdown — the 40% on the secondary source affects net hourly rate substantially. Couples with high earners should consider whether the lower-earning partner can take the work to access basic rate.

Regional differences (Scotland, Wales, Northern Ireland)

Tax codes are issued by HMRC and apply to UK-wide employees. Scotland uses tax codes prefixed "S" (e.g. S1257L) to indicate Scottish income tax bands (Starter 19%, Basic 20%, Intermediate 21%, Higher 42%, Advanced 45%, Top 48%) — the numerical allowance portion is the same as rUK. Wales uses "C" (e.g. C1257L) for Welsh resident, but Welsh rates currently match UK. Northern Ireland uses standard UK codes throughout. The numerical part of the code (e.g. 1257 for £12,570 PA) is identical across the UK; only the prefix changes the band structure.

D0 Tax Code Calculator — UK 2025/26

Tax code calculator