Use it or lose it before 5 April. ISA allowance, pension contributions, Capital Gains allowance, Marriage Allowance, and more. Complete tax year end checklist.
Tax information is based on HMRC rules for the 2026/27 tax year. Tax rules can change — always verify current rates at GOV.UK. This is not tax advice. Consider consulting a qualified tax adviser for your personal situation.
Contents
Don’t let valuable allowances expire unused. Here’s what to check before 5 April.
Key Dates
Important Deadlines
Date
Event
5 April
Tax year ends
6 April
New tax year begins
Allowances reset
ISA, CGT, dividend, pension annual
Can’t carry forward
Most allowances lost
Planning Timeline
When
Action
February
Review and plan
March
Take action
Early April
Final checks
5 April
Deadline
ISA Allowance (£20,000)
The Basics
Feature
Details
Annual allowance
£20,000
Carry forward
No — use it or lose it
Split between
Cash ISA, Stocks & Shares ISA, LISA
Tax benefit
All growth/interest tax-free
ISA Types
Type
2026-27 Allowance
Cash ISA
Part of £20,000
Stocks & Shares ISA
Part of £20,000
Lifetime ISA
£4,000 max (within £20,000)
Innovative Finance
Part of £20,000
Total across all
£20,000
Action Required
Situation
Action
Haven’t used any
Open ISA, deposit what you can
Partially used
Top up
Don’t have £20k
Put in what you can
Already maxed
You’re done
Quick Wins
If You Have
Do
£100+ spare
Open Cash ISA
Regular savings
Use Regular Saver ISA
Investments outside ISA
Bed and ISA (see below)
Savings goals
Lifetime ISA (if under 40)
Pension Contributions
Annual Allowance
Limit
Details
Standard
£60,000 per year
Earnings cap
Can’t exceed earnings
Carry forward
Up to 3 years unused allowance
High earners
May be tapered
Tax Relief
Tax Rate
On £1,000 Contribution
Basic (20%)
Costs you £800, worth £1,000
Higher (40%)
Costs you £600, worth £1,000
Additional (45%)
Costs you £550, worth £1,000
Action Required
Situation
Action
Employer scheme
Check if can increase contribution
Self-employed
Personal pension contribution
High earner
Use carry forward if available
Under-contributed
Consider lump sum
Carry Forward
How It Works
Details
Unused allowance
From last 3 years
Must have earned
In each year
Use current year first
Then oldest unused
Check records
What did you contribute?
Capital Gains Tax
Annual Exempt Amount
Year
Tax-Free Gains
2026-27
£3,000
Unused
Cannot carry forward
Above this
Taxed at 18%/24%
Bed and ISA
Step
Action
1
Sell investments with gains (up to £3,000 profit)
2
Gains are tax-free
3
Repurchase same investments in ISA
4
Future growth is tax-free
Watch Out
Details
Trading costs
May eat into benefit
30-day rule
Doesn’t apply to bed and ISA
Same-day rebuy
In ISA is fine
Only if gains
No point if losses
Capital Losses
| Can | Offset against gains |
| Carry forward | Unlimited years |
| Report | On Self Assessment |
| Strategy | Realise losses before year end |
Marriage Allowance
What It Is
Feature
Details
Transfer
£1,260 of Personal Allowance
From
Non-taxpayer to basic rate spouse
Worth
£252 per year
Backdate
Up to 4 years
Eligibility
Person
Requirement
Lower earner
Income under £12,570
Higher earner
Basic rate taxpayer (under £50,270)
Relationship
Married or civil partners
Action Required
Step
Action
Check eligibility
Both conditions met?
Apply
gov.uk/marriage-allowance
Claim backdate
Get up to £1,000+ lump sum
Take 5 minutes
Worth doing
Dividend Allowance
Tax-Free Dividends
Year
Allowance
2026-27
£500
Above this
Taxed (8.75%/33.75%/39.35%)
Action Required
Situation
Action
Dividends in ISA
Already tax-free
Dividends outside ISA
Consider Bed and ISA
Company director
Time dividend payments
Gift Aid Donations
How It Works
Feature
Details
Charity claims
25p for every £1 you give
Higher rate taxpayers
Can claim extra 25p back
Must donate
In the tax year
Year End Action
If You
Action
Plan to donate
Do it before 5 April
Higher rate taxpayer
Include in Self Assessment
Made donations
Keep records
Other Allowances
Personal Allowance
| Amount | £12,570 tax-free income |
| Action | Ensure salary sacrifice doesn’t waste it |
| Couples | Can both use own allowance |
| Amount | £1,000 |
| For | Self-employed/side income |
| If under | Don’t need to report |
| If over | Only profit above £1,000 taxed |
Summary: Tax Year End Checklist
Must-Do Before 5 April
Action
Done
Use ISA allowance (any amount)
☐
Review pension contributions
☐
Check Marriage Allowance
☐
Realise gains/losses if needed
☐
Make Gift Aid donations
☐
Check Eligibility
Allowance
Eligible
Using
ISA (£20,000)
☐
☐
Lifetime ISA (£4,000)
☐
☐
Pension (£60,000)
☐
☐
Marriage Allowance
☐
☐
CGT allowance (£3,000)
☐
☐
By Amount to Save
Action
Potential Tax Saving
Marriage Allowance
£252/year
Full ISA (over time)
Hundreds long-term
Pension contribution
20-45% of contribution
CGT allowance
Up to £720
Higher rate Gift Aid
25p per £1 donated
December/January
Action
Done
Review last year’s actions
☐
Check for carry forward (pension)
☐
Plan contributions
☐
February/March
Action
Done
Make pension contributions
☐
Top up ISA
☐
Bed and ISA if applicable
☐
Marriage Allowance claim
☐
Key Contacts
Resource
For
Gov.uk
All applications
HMRC
Tax queries
Pension provider
Contribution deadlines
ISA provider
Transfer times
Business and Self-Employed Checklist
If you’re self-employed or run a side business, there are additional year-end actions to take:
Expenses to Review Before 5 April
Category
Action
Mileage log
Ensure business miles are recorded (45p/mile up to 10,000; 25p beyond)
Working from home
Claim £6/week HMRC flat rate or calculate actual costs
Equipment purchased
Ensure qualifying assets are recorded for capital allowances
Business subscriptions
Paid for this tax year and expensable
Professional development
Training courses directly related to your work
Self-Employed Allowances 2026/27
Allowance
Amount
Notes
Trading allowance
£1,000
If total income below this, nothing to report
Property allowance
£1,000
For property income — separate from trading
Annual Investment Allowance
£1,000,000
100% relief on qualifying plant and machinery
Payments on Account
If you pay Self Assessment tax in advance (Payments on Account), the second payment is due 31 July. If your income has fallen compared to last year, you can apply to reduce your Payments on Account to avoid cash flow strain.
Quick Reference: Key Numbers 2026/27
Allowance / Threshold
Amount
ISA annual allowance
£20,000
Junior ISA
£9,000
Lifetime ISA
£4,000
Pension annual allowance
£60,000
Capital Gains Tax exempt amount
£3,000
Dividend allowance
£500
Personal Savings Allowance (basic rate)
£1,000
Personal Savings Allowance (higher rate)
£500
Personal Allowance
£12,570
Trading / Property allowance
£1,000 each
Key Date
What Happens
5 April
Tax year ends — all use-it-or-lose-it allowances expire
6 April
New tax year begins
31 July
Second Payment on Account for Self Assessment
5 October
Deadline to register for Self Assessment (first time)
31 October
Paper Self Assessment return deadline
31 January
Online SA return and payment deadline
Don’t leave money on the table. Most of these take minutes to action but can save hundreds of pounds. Even if you can only do one thing, use some of your ISA allowance — future you will appreciate the tax-free growth.