How to Track Your ISA, LISA, JISA and Pension Allowances in One Google Sheet (UK 2026)

Every April 5th, the UK tax year closes — and with it, every unused tax-advantaged allowance disappears permanently. You cannot carry most of them forward. You cannot get them back. They simply expire.

For a family with two adults and two children, the combined annual allowances across ISA, LISA, JISA and pension accounts amount to well over £100,000 in tax-sheltered capacity per year. Most families use a fraction of it.

This guide explains each account, shows you the annual limits for the 2025/26 tax year, and gives you a simple Google Sheets framework to track your usage and estimate your tax savings — all in one place.

UK Tax-Advantaged Accounts at a Glance

Account	Annual Allowance	Who Can Use It	Key Benefit
ISA (Adult)	£20,000 per person	UK residents aged 18+	All growth and income tax-free
LISA	£4,000 per person (counts within ISA)	Aged 18–39 to open, 18–49 to contribute	25% government bonus (up to £1,000/year)
JISA	£9,000 per child	Children under 18	Independent allowance — does not reduce adult ISA
Pension / SIPP	£60,000 or 100% of earnings (lower applies)	UK taxpayers	Tax relief at your marginal rate on contributions

Understanding Each Account

1. ISA — £20,000 per adult per year

The Individual Savings Account is the most widely known UK tax wrapper. Contributions come from post-tax income, but all investment growth, dividends and withdrawals are completely free of UK tax — forever.

Each adult has a separate £20,000 allowance. It does not transfer between spouses. For a couple, that is £40,000 in combined ISA capacity each year. You can split it across Cash ISA and Stocks & Shares ISA as you choose, but the combined total cannot exceed £20,000 per person.

2. LISA — £4,000 per year + 25% government bonus

The Lifetime ISA is one of the most underused accounts in the UK. For eligible savers, the government adds a 25% bonus on top of contributions — meaning a maximum £1,000 free money each year, simply for saving.

Eligibility requires opening the account before age 40, and contributions are only permitted up to age 50. The funds can be used penalty-free for either a first home purchase (on properties up to £450,000) or from age 60. Withdrawing for any other reason incurs a 25% penalty — which effectively returns the bonus and takes a small slice of your own money too.

Important: LISA contributions count within your £20,000 ISA allowance, not on top of it.

3. JISA — £9,000 per child per year

The Junior ISA is a powerful and under-appreciated vehicle. Each child under 18 has their own £9,000 annual allowance — completely separate from adult ISA limits. A family with two children has £18,000 per year in additional tax-sheltered capacity.

The child gains control of the account at age 18. Funds cannot be withdrawn before then (except in very limited circumstances). This makes JISA ideal for long-term compounding of education or first-home savings.

4. Pension / SIPP — £60,000 per year

Pension contributions benefit from tax relief at your marginal rate — meaning a 40% taxpayer effectively pays only £60 for every £100 of pension contribution. This makes pension contributions the highest-return "investment" available to higher-rate taxpayers before even considering investment growth.

The £60,000 annual allowance includes employer contributions, employee contributions, and any personal contributions to a SIPP. If your earnings are below £60,000, the allowance is capped at 100% of your earnings.

An additional rule worth knowing: Carry Forward. If you have unused pension allowances from the previous three tax years, you may be able to contribute up to £180,000 in a single year — subject to earnings. This is particularly valuable for high earners in a good year or the self-employed with variable income.

Why Most Families Don't Track This

The allowances above are well-documented on HMRC's website — but knowing they exist and actively tracking usage against them are two very different things. The most common barriers I see:

• Fragmentation: ISA at one provider, pension at an employer, SIPP at another, LISA at a third — no unified view
• Annual reset pressure: Most people think about ISA allowances in March, when it's almost too late
• No calculation of savings: The actual tax saving is abstract until you put a number on it
• Children's accounts overlooked: JISA is set up once at birth and then ignored for years

Building a Tracker in Google Sheets

A good tracker needs to answer four questions at a glance:

1. How much have I contributed to each account this tax year?
2. How much allowance do I have remaining?
3. What government bonus am I on track to receive (LISA)?
4. What is my estimated annual tax saving from pension contributions?

Here is the minimum structure you need for a functional tracker:

Account	Contributed This Year	Annual Limit	Remaining	Status
My ISA	[Your input]	£20,000	=Limit − Contributed	🟡 / 🟢 / ✅
Partner ISA	[Your input]	£20,000	=Limit − Contributed	🟡 / 🟢 / ✅
LISA	[Your input]	£4,000	=Limit − Contributed	Bonus = Contributed × 25%
JISA (Child 1)	[Your input]	£9,000	=Limit − Contributed	🟡 / 🟢 / ✅
Pension (annual)	=Monthly × 12	£60,000	=Limit − Annual total	Tax saving = Total × rate

The key formula for pension tax savings is straightforward: if you contributed £15,000 this year and your marginal tax rate is 40%, your estimated saving is £6,000. That is money that would have gone to HMRC, now working for your retirement.

Taking It Further: A Full Family Wealth Framework

A standalone allowance tracker is a good start — but it is still just one piece of a complete family wealth picture. The most common follow-on questions I hear from families who build a tracker are:

• "I know I'm using my ISA, but am I on track for my actual goals?"
• "How does my pension balance compare to what I need to retire at 60?"
• "What return do I need to hit my targets — and is that realistic?"
• "We have assets across multiple countries. How do we see the full picture?"

These are the questions that led me to build the Family Wealth Architecture Toolkit — a 10-tab Google Sheets framework that connects allowance tracking to goal planning, funded ratio analysis, human capital estimation, and a complete family wealth dashboard.

Key Takeaways

• The UK tax year runs from 6 April to 5 April the following year. Unused allowances cannot be carried forward (except pension carry forward rules).
• A family with two adults and two children has over £109,000 in combined annual allowance capacity.
• The LISA 25% bonus is one of the highest guaranteed returns available in the UK — but only for eligible savers with qualifying purposes.
• Pension contributions at the 40% tax rate effectively halve the cost of building retirement wealth.
• Tracking is the prerequisite for optimising. Without a system, most families underuse their allowances by default.