April 5 is the line UK investors trip over more than any other date in the tax calendar. Allowances reset at midnight, contribution windows close, and the things you meant to do "next month" become things you can no longer do at all. This is a checklist of actions self-directed investors commonly review before the deadline — not as a recipe to follow blindly, but as a list of items to walk through with a clear head before the year flips over.
This is not financial advice. Past performance does not guarantee future returns. Consider speaking to an FCA-authorised financial adviser for personalised guidance.
The 2026/27 allowances referenced throughout this article are: ISA £20,000, LISA £4,000 (counted within the ISA limit), CGT annual exempt amount £3,000, dividend allowance £500, and the SIPP annual allowance of £60,000 or 100% of earnings (whichever is lower). These figures are correct as of the current tax year but are subject to change in any Budget.
Why April 5 is the deadline that matters
The UK tax year runs 6 April to 5 April. Allowances are use-it-or-lose-it on a year-by-year basis with limited carry-forward. The ISA allowance is the cleanest example: any unused portion of £20,000 simply disappears at midnight on 5 April. The same applies to the £4,000 LISA bonus window, the £3,000 CGT annual exempt amount and the £500 dividend allowance.
A few allowances do carry forward — pension annual allowance carries forward up to three previous tax years, provided you were a member of a registered pension scheme during those years. The carry-forward rules are tight and depend on having earnings to support the contribution.
A UK investor who reaches 5 April without using their allowances has irreversibly forgone tax efficiency for that year. Anything held outside a wrapper continues compounding under CGT and dividend tax — so the cost of "I'll do it next year" compounds with the portfolio.
ISA £20,000 — pro-rated mechanics and split allowances
The ISA allowance is £20,000 across all ISA types combined. You can split it however you like across Stocks and Shares ISA, Cash ISA, Innovative Finance ISA and Lifetime ISA — provided you stay within £20,000 in total and within £4,000 in the LISA specifically.
Common shapes investors review at year-end:
- Stocks and Shares only. £20,000 into a single S&S ISA. Simple, common, and tax-efficient for long-horizon equity exposure.
- LISA + S&S split. £4,000 into LISA (for the 25% government bonus), £16,000 into S&S ISA. Available to investors aged 18–39 at first contribution and continuing until age 50.
- Cash + S&S split. Cash ISA for short-term reserves, S&S ISA for long-term growth. The split is a personal asset-allocation question, not a tax question.
The ISA allowance does not pro-rate by month. If you only realise on 1 April that you have £15,000 of headroom, you can contribute the entire £15,000 in the final five days. Some investors deliberately back-load contributions to keep cash productive elsewhere; others front-load on 6 April for maximum compounding time. Both are reasonable.
Things to verify before the deadline:
- Provider funding cut-off. Most platforms accept ISA contributions up until midnight on 5 April but cleared-funds requirements differ. A bank transfer initiated on 4 April may not clear in time. Debit card top-ups usually settle same-day.
- Flexible vs non-flexible ISAs. A flexible ISA lets you withdraw and replace within the same tax year without using fresh allowance. Not all S&S ISAs are flexible — Hargreaves Lansdown is, AJ Bell is, Vanguard's S&S ISA is not. Check before relying on the feature.
- One ISA per type per tax year (rule changed April 2024). Since the 2024/25 tax year, you can subscribe to multiple ISAs of the same type within a single tax year, splitting your allowance across providers. Worth confirming your current provider's stance — some platforms still display the old single-provider rules in their UI.
LISA £4,000 + 25% government bonus deadline
The Lifetime ISA is overlooked by many investors because of its restrictions, but the 25% government bonus on contributions up to £4,000 per year is the most generous match available to UK retail investors who qualify.
The structural points:
- Open before age 40, contribute until age 50.
- £4,000 annual contribution cap; £1,000 government bonus paid monthly on contributions.
- Withdraw without penalty for first home (under £450,000), at age 60, or if terminally ill.
- 25% withdrawal charge for any other use — which effectively reclaims the bonus and a small penalty.
For investors with a multi-year horizon to a first home or retirement at 60+, the 25% LISA bonus is exceptionally generous compared to typical investment returns on the contribution itself, though the underlying investments inside the LISA still carry market risk and the bonus is subject to qualifying-use rules (first home under £450,000 or withdrawal at age 60+). The deadline mechanics are the same as the ISA — contributions must be made by 5 April.
A planning note many investors discuss with advisers: the LISA contribution counts within the £20,000 overall ISA allowance. So £4,000 LISA + £16,000 S&S ISA is the maximum split, not £4,000 LISA + £20,000 S&S ISA.
CGT £3,000 annual exempt amount and bed-and-ISA
The CGT annual exempt amount is £3,000 for 2026/27 — down from £12,300 just a few years ago. The reduction has changed the year-end planning conversation materially. What used to be a comfortable buffer now caps very small disposals before CGT bites.
Two related actions investors review:
Realising gains to use the £3,000 allowance.
If you have unrealised gains in a GIA and have not used your CGT allowance, selling enough to realise £3,000 of gain (and optionally rebuying after a 30-day window, or via a different fund / wrapper) can reset your cost basis without paying CGT. This is sometimes described as "harvesting" the allowance. The 30-day rule on rebuying the same security in a GIA exists to prevent this — but bed-and-ISA and bed-and-spouse mechanics work around it legitimately.
Bed-and-ISA: selling in GIA and rebuying inside an ISA.
Many platforms offer a single-transaction "bed-and-ISA" service. You sell a holding in your GIA, the platform contributes the proceeds to your ISA, and rebuys the same security inside the ISA wrapper. The mechanics:
- The GIA sale is a CGT event — gain or loss realised against your annual exempt amount.
- The ISA purchase uses up that year's ISA allowance.
- The 30-day rule does not apply because the ISA purchase is in a different "person" for CGT purposes (you in your ISA wrapper).
This is a way to migrate unwrapped holdings into an ISA over time, using the £3,000 CGT allowance plus £20,000 ISA allowance each year. The process is cleaner if you do it before year-end, as some platforms suspend bed-and-ISA processing in the final couple of days of the tax year.
Bed-and-spouse for couples.
A married couple or civil partners can transfer holdings between each other at no-gain-no-loss, then one spouse sells. This effectively doubles the CGT allowance available across the couple. The mechanics require the inter-spouse transfer to be genuine (not a sham), but the technique is well-established.
Pension contributions and carry-forward
Pension top-ups before year-end serve two purposes: using the current year's £60,000 annual allowance, and using carry-forward from up to three previous tax years.
The key constraints to verify:
- Annual allowance. £60,000 or 100% of relevant UK earnings, whichever is lower.
- Tapered annual allowance. For high earners with adjusted income above £260,000, the annual allowance tapers down to a minimum of £10,000.
- Money Purchase Annual Allowance (MPAA). Once you have flexibly accessed a defined-contribution pension, your annual allowance for further DC contributions falls to £10,000.
- Carry-forward. You can carry forward unused annual allowance from the three previous tax years, provided you were a member of a registered pension scheme in those years. Carry-forward must be used in chronological order — oldest year first.
For investors with variable income (founders, contractors, bonus-driven earners), carry-forward is the mechanism that lets a high-income year mop up allowance from quieter previous years. Worth modelling before the deadline rather than discovering after.
A platform-mechanics note: SIPP contributions usually need to clear before midnight on 5 April to count for the current tax year. Some providers process SIPP contributions T+1, so a 4 April contribution may not technically count if it does not settle in time. Most providers publish a "tax year end deadline" for guaranteed processing, often around 30 March.
JISA + JSIPP for kids
If you have children, the year-end checklist extends to their wrappers too.
Junior ISA (JISA). £9,000 annual allowance. Subscriptions must be made by 5 April. The wrapper sits in the child's name and locks until age 18, at which point it converts to an adult ISA. Both Stocks and Shares JISA and Cash JISA are available, with the same £9,000 combined cap.
Junior SIPP. Children with no earnings can still contribute up to £2,880 net per year, which the government grosses up to £3,600 with basic-rate relief. Locked until age 57 (or whatever the minimum pension age is when they retire). Long-horizon compounding on a small annual contribution can be substantial — fifty years of equity returns on £3,600/year is the kind of number that surprises parents.
Both are personal-finance decisions with real intergenerational implications. Worth thinking about before the deadline rather than as an afterthought.
Self-assessment dividend reconciliation
For investors who file Self Assessment — including most who realise CGT above the allowance, receive dividends above £500 outside an ISA, or have other untaxed income — year-end is the practical moment to reconcile what platforms will report against what you have logged.
Common items to verify in March/April:
- GIA dividend statements — most platforms publish a tax certificate in April–May.
- REIT PID dividends — taxed as property income, not ordinary dividends. Verify both gross and net figures.
- Foreign withholding tax — US dividends withheld at 15% under W-8BEN. You can typically claim foreign tax credit relief.
- Realised CGT — disposal value, cost basis (Section 104 rules), and gain need calculation. Tools like Sharesight automate this.
Doing this reconciliation in March/April gives time to spot platform errors before they harden into the tax certificate you submit on.
How aggregation tools surface "unused allowance"
The investor who reaches 5 April with unused ISA headroom usually did so because the headroom was not in front of them. Allowance utilisation is a number, but the number lives across multiple platforms — the ISA is at one provider, the LISA at another, the SIPP at a third, the GIA at a fourth.
Aggregation tools that pull positions and contributions across wrappers can surface a consolidated "tax-year-end view": ISA contributed YTD, LISA contributed YTD, SIPP contributed YTD, gains realised in GIA YTD against the £3,000 allowance. This view changes the planning conversation from "I think I've used most of my ISA" to "I have £4,200 of headroom left across three wrappers".
Current UK portfolio trackers handle this with varying success. Sharesight tracks contributions if you tag transactions correctly but does not natively model wrappers. Snowball is income-focused. Spreadsheets work if maintained. Newer wrapper-aware tools (Invormed is being built around this case) treat ISA / SIPP / GIA / LISA as first-class citizens with explicit allowance tracking. The point is that visibility of unused allowance, before 5 April, is the single biggest driver of whether the year-end actions actually get done.
A worked sequence for the final week
If you are walking through this with a week or two left:
- Pull contribution statements from each ISA, LISA and SIPP provider. Compare against £20,000, £4,000 and £60,000 (or earnings) respectively.
- Pull GIA realised gains YTD. Compare to £3,000 CGT exempt amount.
- Decide on top-ups (ISA, LISA, SIPP) and disposals (bed-and-ISA, gain harvesting).
- Action via platforms — by the platform's published deadline, often 30 March, not 5 April.
- Update self-assessment records — disposals, dividend totals, foreign tax paid.
Steps 1–2 are the visibility step. Steps 3–4 are the action step. Step 5 is the records step.
FAQ
Can I use my ISA allowance any time before April 5?
Yes. The £20,000 allowance is annual, not pro-rated by month. You can contribute the full amount on 6 April or split it across the year — provided contributions clear before midnight on 5 April. Most platforms publish a recommended cut-off a few days earlier (often 30 March) to ensure clearance.
What's bed-and-ISA?
A single-transaction service offered by most UK platforms where you sell a holding in your GIA and rebuy the same security inside your ISA. The GIA sale is a CGT event (which can use your £3,000 annual exempt amount), and the ISA purchase uses up that year's ISA allowance. It's the standard mechanism for migrating unwrapped holdings into a tax-protected wrapper over time.
Can I still pay into a SIPP after the tax-year-end?
You can contribute to a SIPP at any time, but contributions only count toward the current tax year if they clear before 5 April. Contributions made on 6 April count toward the new tax year's allowance. Carry-forward of previous years' allowance applies in the year you make the contribution, so missing 5 April does not lose carry-forward — it just defers it.
What's the CGT allowance now?
£3,000 for the 2026/27 tax year. This is significantly lower than the £12,300 it used to be — the reduction over recent years has changed the year-end planning calculus for investors with material GIA holdings. It is per individual, so couples have £6,000 between them via inter-spouse transfers.
Should I sell to use my CGT allowance?
A common consideration but not universally applicable. Selling to realise £3,000 of gain resets cost basis without CGT cost, but only makes sense if you had the gain to realise and want to keep the position. Bed-and-ISA goes a step further by moving the holding into a tax-protected wrapper. Whether either is right for your situation depends on your overall tax position — worth discussing with an FCA-authorised adviser.
Do tax-year-end actions affect my self-assessment?
Yes. Disposals in your GIA are reportable on your tax return for the year they occur. Pension contributions affect your tax position via relief. Dividend income above £500 is reportable. Anything you do before 5 April flows into the return covering 6 April – 5 April; anything after counts for the next year.
Invormed is in early access — join the early-access waitlist.