HMRC P6 Notice – Full Guide to Tax Code Notifications, How Employers Must Apply P6 Codes, and How P6 Works Under RTI

Understanding the HMRC P6 Notice

The HMRC P6 Notice is a digital notice sent to employers through HMRC systems to instruct them to change an employee’s tax code. Unlike forms that employees complete (such as Starter Checklists or P45s), the P6 is an employer-facing notification generated automatically by HMRC whenever an employee’s tax code needs to change.

P6 notices are essential for ensuring correct PAYE deductions. They are used thousands of times every day to fix tax codes caused by:

• Starting a new job

• Ending a job

• Receiving benefits in kind

• Claiming marriage allowance

• Changes in student loan status

• Pension income

• Correcting emergency tax

• HMRC reviewing taxpayer circumstances

• Underpayments and PAYE adjustments

The P6 is one of the most important tools HMRC uses to make sure that the right amount of tax is deducted.

This guide explains everything about P6 notices — how they work before and after RTI, how employers must apply them, and how employees can fix incorrect tax codes.

Audit Consulting Group prepared this full guide to help both employers and employees understand P6 notices and keep PAYE accurate.

What Is an HMRC P6 Notice?

The P6 notice is an instruction from HMRC to the employer to apply a new or updated tax code for a specific employee. HMRC sends it electronically through the employer’s PAYE Online account or via payroll software.

A P6 notice includes:

• The employee’s name and NI number

• The new tax code HMRC wants the employer to use

• Whether the code should be operated on a cumulative or Week 1/Month 1 basis

• Any adjustments needed (e.g., underpayments, marriage allowance, benefits, allowances)

• The effective date the new tax code must start

Before the digital age, P6 notices were paper forms mailed to employers.
Now they are entirely electronic through RTI.

What Triggers a P6 Notice?

HMRC issues a P6 whenever they need an employer to apply a revised tax code.

Common triggers include:

Employee starts a new job

HMRC updates records and sends a corrected tax code.

Employee provides a Starter Checklist

HMRC processes the information and sends a P6.

Employee submits a Self Assessment

Results may trigger a new tax code (to recover tax owed).

Claiming Marriage Allowance

HMRC adjusts tax codes for both partners.

Receiving benefits in kind

For example:

• Company car

• Private medical insurance

• Fuel benefit

Employer files a P11D

Benefits in kind require updated tax codes.

Student loan changes

Plan 1, Plan 2, Plan 4, or postgraduate loan status updates.

Repayment of underpayments

HMRC may collect past tax owed through a tax code adjustment.

Stopping or starting pension income

Employee changes jobs mid-year

HMRC recalculates allowances.

P6 vs. Other HMRC Notices

Employers often confuse P6 with other notices. Here is the difference:

The P6 is specifically an employer instruction.

How the P6 Works Under RTI (Real Time Information)

Before RTI (pre-2013), employers filed year-end returns and HMRC issued P6 notices by post.

Since RTI was introduced in 2013, P6 notices are:

• Automatic

• Electronic

• Delivered instantly via payroll software

• Integrated with FPS submissions

Under RTI, P6 notices interact directly with payroll:

• Employer receives P6

• Employer updates payroll with new tax code

• Next FPS submission includes updated tax code

• HMRC adjusts tax calculation

• Refund or adjustment is applied automatically

This system ensures tax codes remain accurate throughout the year.

What a P6 Notice Contains

A P6 typically includes:

• Employee’s new tax code

e.g., 1257L, 1283L, K489, BR, D0, NT

• Effective date

When the employer must apply the change.

• Whether cumulative or Week 1/Month 1

Cumulative = recalculates year-to-date tax.
W1/M1 = avoids recalculation (used when correcting emergency tax).

• Adjustments

May include:

• Underpayment collection

• Job expenses allowances

• Marriage allowance transfer

• Blind person’s allowance

• Benefits in kind adjustments

• Student loan flag

Payroll must operate the correct plan.

• Postgraduate loan flag

• Employer instructions

How to apply the code in payroll software.

How Employers Must Apply the P6 Notice

Step 1: Check the P6 notice

View through:

• Payroll software

• HMRC PAYE Online
  https://www.gov.uk/paye-online

Step 2: Update payroll system

Enter the new tax code exactly as shown.

Step 3: Check effective date

Usually applied from:

• The next payroll

• The next FPS submission

Step 4: Re-run payroll if required

If the notice requires cumulative adjustments.

Step 5: Submit FPS

The new tax code is included in the submission.

Step 6: HMRC updates tax calculations

This may refund overpaid PAYE or collect underpayments.

What Happens If Employers Ignore a P6 Notice?

Ignoring or delaying a P6 notice causes:

• Incorrect PAYE deductions

• Tax code errors

• Underpayments

• Overpayments

• HMRC penalties

• Employee complaints

• Payroll audits

Employers are legally required to act.

How P6 Notices Affect Employees

Employees may notice:

• Change in take-home pay

• Repayment of overpaid tax

• Adjustments for underpaid tax

• Correction of emergency tax

• Updated tax code on payslip

Employees can track tax codes via:
https://www.gov.uk/personal-tax-account

Emergency Tax and the P6 Notice

Most emergency tax issues are resolved with a P6 notice.

Typical emergency tax codes include:

• 1257L W1/M1

• 0T W1/M1

• BR

• X tax codes

When HMRC receives updated information, it issues a P6 to correct the code.

When HMRC Sends a P6 Notice

HMRC may issue a P6 after:

New employment begins

HMRC receives P45 or Starter Checklist.

Employee updates details

Through their Personal Tax Account.

Marriage allowance approval

HMRC adjusts both partners’ codes.

Employer files P11D

Benefits in kind adjustments.

Pension income starts

HMRC recalculates allowances.

Employee changes job

HMRC reassesses income.

Year-end reconciliation

Underpayments collected via tax code.

Student loan changes

Taxpayer submits Self Assessment

The P6 is triggered automatically by HMRC’s system.

How Employees Can Fix Incorrect Tax Codes

Employees can correct their tax code by using:

• HMRC Personal Tax Account

https://www.gov.uk/personal-tax-account

• “Check your tax code” online tool

https://www.gov.uk/check-income-tax-current-year

• Calling HMRC

0300 200 3300

• Advising employer of missing starter information

HMRC will then send a P6 to the employer.

How Employers Correct Errors Caused by Wrong Application of a P6

If an employer applies a tax code incorrectly:

Submit corrected FPS

Adjust payroll records

Apply the correct cumulative or W1/M1 setting

Update student loan flags

Recalculate year-to-date tax

Audit Consulting Group frequently handles complex corrections for employers.

Common Problems With P6 Notices

Employees:

• Incorrect tax code

• Emergency tax deductions

• Higher tax due to benefits

• Student loan applied incorrectly

• Underpayments appearing unexpectedly

Employers:

• Failure to apply P6 codes

• Duplicate notices

• Conflicting tax codes for same employee

• Missing starter information

• Incorrect NI category

These issues are extremely common and easy to fix with professional support.

Case Studies

Case Study 1 – Emergency Tax Code Corrected

Client: Tom H., Manchester
Issue: Started job without P45 → emergency tax applied.
Solution: HMRC issued P6; employer updated code.
Outcome: £460 refunded.

Case Study 2 – Employer Ignored Tax Code Change

Client: London marketing agency
Issue: Employee’s P6 not applied → underpayment.
Solution: We corrected historic FPS and resolved HMRC charges.

Case Study 3 – Marriage Allowance Not Applied

Client: Laura & Ian T., Edinburgh
Issue: HMRC issued P6 but employer failed to update payroll.
Outcome: We liaised with HMRC, corrected code, refund paid.

Case Study 4 – Student Loan Plan Incorrect

Client: Sarah N., Birmingham
Issue: Wrong plan applied → overpayment.
Solution: P6 issued, payroll corrected, refund processed.

Frequently Asked Questions (FAQ)

Q1: What is a P6 notice?

An HMRC instruction telling employers to apply a new tax code.

Q2: Do employees receive P6 notices?

No — P6 is only for employers.
Employees receive a P2.

Q3: Does a P6 mean I owe tax?

Not always. It may be for a refund or an adjustment.

Q4: How long does it take for P6 to be applied?

Usually within 1–2 payroll cycles.

Q5: What if my employer doesn’t apply the P6?

Your tax will be wrong until they update payroll.
We can assist in resolving employer delays.

Q6: How do I check if my tax code changed?

Through your HMRC Personal Tax Account.

Q7: Why did my tax code go to Week 1/Month 1?

HMRC wants to avoid recalculating the whole year.

Official HMRC guidance:
https://www.gov.uk/payroll-real-time-information