When does the UK tax year end?

The UK tax year runs from April 6th to April 5th. Any allowances you don't use by April 5th are lost forever (most can't carry forward). This makes late March/early April crucial for tax planning.

What happens to my ISA allowance if I don't use it?

Your £20,000 annual ISA allowance expires on April 5th each year. You cannot carry unused amounts forward. If you can afford to save, maxing out your ISA before year-end protects future growth from tax permanently.

Should I make pension contributions before tax year end?

If you haven't used your pension annual allowance (£60,000 or 100% of earnings), contributing before April 5th gets tax relief this year. You can also carry forward unused allowances from the previous 3 years if you qualify.

What tax year end actions save the most money?

Biggest savers: use ISA allowance (protect investment growth from tax), pension contributions (40-60% tax relief for higher earners), using Capital Gains Tax allowance (£3,000), and gifting to use inheritance tax exemptions.

Tax Year End Guide UK — What to Do Before April 5th | PocketWise

Don’t let valuable tax allowances expire. Here’s your checklist for actions before April 5th.

Key Deadlines Summary

Use It or Lose It Allowances

Allowance	Amount	Deadline
ISA	£20,000	April 5th
LISA	£4,000 (within ISA)	April 5th
Junior ISA	£9,000	April 5th
Pension annual allowance	£60,000	April 5th
Capital Gains Tax allowance	£3,000	April 5th
Dividend allowance	£500	April 5th
Annual gift exemption	£3,000	April 5th

ISA Allowance

Why It Matters

What You Get	Benefit
£20,000 annual limit	Tax-free
Interest	No tax ever
Dividends	No tax ever
Capital gains	No tax ever

Types of ISA

ISA Type	Limit	Best For
Cash ISA	£20,000 total	Short-term savings
Stocks & Shares ISA	£20,000 total	Long-term growth
Innovative Finance ISA	£20,000 total	P2P lending
LISA	£4,000 (part of £20k)	First home/retirement

Action Checklist

Task	Priority
Check current ISA balance	High
Top up if under £20,000	High
Open ISA if don’t have one	High
Consider which type for needs	Medium

Last-Minute ISA Tips

Tip	Why
Open account first	Even with £1
Can add more later	Before deadline
One of each type	Per tax year
Transfer old ISAs anytime	Doesn’t use allowance

Pension Contributions

Annual Allowance

Allowance	Amount
Standard	£60,000
Or 100% of earnings	Whichever lower
Carry forward	3 years if unused

Tax Relief

Tax Band	Relief on £1,000
Basic rate (20%)	£250
Higher rate (40%)	£500
Additional rate (45%)	£563

Carry Forward Rules

Year	Unused Can Use
2022/23	Yes
2023/24	Yes
2024/25	Yes
2021/22	Expired

Action Checklist

Task	Priority
Check pension contributions YTD	High
Calculate remaining allowance	High
Check carry forward available	High
Make additional contribution	High if affordable

Salary Sacrifice

If You Can	Do This
Arrange by early March	Give payroll time
One-off bonus sacrifice	Before year end
NI saving too	Salary sacrifice bonus

Capital Gains Tax

Annual Exemption

Detail	Amount
2025/26 exemption	£3,000
Gains above exempt	Taxed

Bed and ISA

Strategy	How
Sell investments	Crystallise gain
Rebuy in ISA	Same day
Use CGT allowance	£3,000 tax-free
Future growth	Tax-free in ISA

Bed and Spouse

Strategy	How
Sell investments	Crystallise gain
Spouse rebuys	Different person
Both use allowance	£6,000 combined

Losses

Action	Benefit
Crystallise losses	Before April 5th
Offset against gains	Reduce tax
Carry forward	Unlimited

Dividend Allowance

Current Allowance

Tax Year	Dividend Allowance
2025/26	£500

Action

If You Have Dividends	Consider
Over £500	Move to ISA before year end
In private company	Timing of dividends
Portfolio	Rebalance into ISA

Marriage Allowance

What It Is

Transfer	Amount
From non-taxpayer	£1,260 of allowance
To basic rate spouse	Saves £252/year

Backdating

Can Claim	Value
4 tax years back	Up to ~£1,000

Action

Check	Do
One spouse non-taxpayer?	Claim
Not yet claimed?	Backdate
Before April 5th	For this year

Gift Exemptions

Annual Exemptions

Exemption	Amount
Annual gift	£3,000
Small gifts	£250 per person
Wedding (parents)	£5,000
Wedding (grandparents)	£2,500

Inheritance Tax Planning

Action	Benefit
Use £3,000 exemption	Reduces estate
Carry forward 1 year	£6,000 if unused last year
Regular gifts from income	Exempt if pattern

Employer Benefits

Use Before Year End

Benefit	Action
Childcare vouchers	Order by March
Eye care vouchers	Use allowance
Employee discounts	Before expiry
Annual wellness budget	If provided

Salary Sacrifice Options

Option	Deadline
One-off pension boost	Early March
Reduce taxable income	Before year end

Income Management

For High Earners

If Income £100k-£125k	Consider
Pension contribution	Restore Personal Allowance
Timing of bonuses	Manage tax band
Gift Aid	Reduce adjusted income

Child Benefit Clawback

If Earning £50k-£60k	Action
Pension contribution	Reduces income
May keep Child Benefit	Below £50k threshold

Self-Assessment

Key Dates

Date	Action
By April 5th	Use allowances
By October 31st	Paper return deadline
By January 31st	Online return + payment

Check Before Year End

Task	Priority
Estimate tax bill	Plan payment
Payments on account	Correct?
Claim all reliefs	Before filing

Month-by-Month Checklist

February

Task	Status
Review ISA contributions	□
Check pension YTD	□
Plan CGT usage	□

March

Task	Status
Top up ISA	□
Additional pension if affordable	□
Bed and ISA transactions	□
Use gift exemptions	□

Early April (Before 5th)

Task	Status
Final ISA top-up	□
Last pension contributions	□
Complete CGT planning	□
Check all allowances used	□

Quick Wins Summary

Action	Tax Saving (Higher Rate)
Use £20k ISA	Future gains tax-free
Extra £10k pension	£4,000 back
Use £3k CGT	Saves £540
Marriage allowance	£252
Gift £3k	IHT saving (40% eventually)

Common Mistakes

Mistake	Avoid By
Leaving ISA until April 4th	Plan in February
Forgetting carry forward	Check 3-year history
Missing deadlines	Set calendar reminders
Not opening accounts	Open early, contribute later

Summary

Deadline	Allowance	Amount
April 5th	ISA	£20,000
April 5th	Pension	£60,000
April 5th	CGT	£3,000
April 5th	Dividends	£500
April 5th	Gifts	£3,000
January 31st	Self-Assessment	N/A

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Contents

Key Deadlines Summary

Use It or Lose It Allowances

ISA Allowance

Why It Matters

Types of ISA

Action Checklist

Last-Minute ISA Tips

Pension Contributions

Annual Allowance

Tax Relief

Carry Forward Rules

Action Checklist

Salary Sacrifice

Capital Gains Tax

Annual Exemption

Bed and ISA

Bed and Spouse

Losses

Dividend Allowance

Current Allowance

Action

Marriage Allowance

What It Is

Backdating

Action

Gift Exemptions

Annual Exemptions

Inheritance Tax Planning

Employer Benefits

Use Before Year End

Salary Sacrifice Options

Income Management

For High Earners

Child Benefit Clawback

Self-Assessment

Key Dates

Check Before Year End

Month-by-Month Checklist

February

March

Early April (Before 5th)

Quick Wins Summary

Common Mistakes

Summary

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Sources