Tax-year-end SIPP top-up near £100k

Start with gross reduction, then find cash needed

The amount of ANI above the childcare limit gives the gross contribution required in this model. A personal pension or SIPP payment is entered as cash actually paid, before the provider adds relief. The cash payment and the gross pension contribution are therefore different numbers. Use the SIPP row to see the payment, the provider top-up and any further tax refund separately.

A final after-tax cost is useful for comparing routes, but it is not the cash balance needed to make the payment. The further refund is not assumed to be available upfront. Keep enough room in the budget for the cash payment itself and use the calculated refund as a separate part of the planning illustration. The calculator does not submit a tax claim or make a pension payment.

The 5 April deadline

SIPP payments must be made by 5 April to count for this tax year. Check the provider’s payment and processing timing. This guide does not assume that starting an instruction is the same as completing a payment, or that a later refund changes the year in which cash was paid. Keep a record of the payment and which tax year your estimate covers.

Recheck the number before transferring cash

Include your bonus, taxable benefits and full other income before calculating the top-up. Enter existing pension cash once, and add Gift Aid separately. A large excess or other income is a reason to discuss the wider position with an adviser. The model is an income-tax illustration, not an assessment of every pension limit or a guarantee that a particular contribution is suitable.

Build the annual estimate before choosing a route

Use gross salary before any salary sacrifice. Add bonus, taxable benefits and full other income, including savings interest, dividends and rental profit covered by allowances. Then enter each existing pension contribution in its correct category. Salary sacrifice and net pay entries are gross amounts. Personal pension cash is the amount actually paid before the provider adds relief. Gift Aid cash is grossed up separately. These distinctions can change the remaining excess substantially, even when the headline salary is the same. Keep a record of the inputs and the assumptions so you can revisit them when circumstances change.

Check the partner independently rather than combining incomes or transferring one parent’s excess to the other. The upper income limit is an each-parent rule, and a minimum income condition also applies. A contribution calculated for one parent cannot establish eligibility for a household whose partner remains over the limit. If the result flags a partner or minimum income issue, resolve that question before treating the childcare amount as protected.

Read value at stake as an estimate, not a cash award

Children have different free-hours values. In England, eligible children from nine months to two years risk all working-parent hours, while children aged three to four retain universal hours. School-age children and children under nine months have no free-hours value in this model. Outside England it counts Tax-Free Childcare only because national free-hours rules differ. The hourly value is an editable planning assumption, so check it against the childcare you would otherwise pay for.

Add paid childcare excluding free hours if you want a bill-based Tax-Free Childcare estimate. A blank bill uses the annual cap and makes the result an up-to value. Entering zero means there is no paid childcare to value. Neither a cap nor an hourly valuation guarantees a place, a payment or full eligibility. The useful comparison is the support this contribution could protect against its estimated final cost, while keeping the pension added visible as a separate amount.

Separate today’s cash from pension savings

The same gross pension addition can have different cash flows across salary sacrifice, workplace net pay and a personal pension or SIPP. The route table separates pay or cash given up, provider top-up, any further Self Assessment refund and final cost. Tax relief is the difference between the engine’s income tax calculation before and after the contribution. It is not a fixed assumption that every contribution costs the same proportion of its gross value.

SIPP payments must be made by 5 April to count for this tax year. Check timing with the provider. The final cost may be lower than the cash needed upfront because relief and refunds do not all arrive together. If the estimated net cash gain is negative, the pension route may not pay in cash terms. A larger excess or other income is a reason to discuss the wider position with an adviser rather than choosing from a headline alone.

Questions about this guide

Sources and assumptions

Each rule has a source and checked date. Editable values, examples and product warning margins are labelled assumptions. Confirm individual eligibility with official guidance.

• tax: https://www.gov.uk/government/publications/rates-and-allowances-income-tax/income-tax-rates-and-allowances-current-and-past
• ani: https://www.gov.uk/guidance/adjusted-net-income
• hours: https://www.gov.uk/free-childcare-if-working/what-youll-get
• eligibility: https://www.gov.uk/tax-free-childcare/check-if-youre-eligible
• tfc: https://www.gov.uk/tax-free-childcare
• ni: https://www.gov.uk/national-insurance-rates-letters
• cap: https://www.gov.uk/government/publications/changes-to-salary-sacrifice-for-pensions-from-april-2029/changes-to-salary-sacrifice-for-pensions-from-april-2029
• pledge: https://www.itv.com/news/2026-10-03/tories-pledge-to-end-100000-childcare-cliff-edge-on-eve-of-conference