On Maternity Leave and Money Is Tight: Pension or ISA First?

The Real Cash-Flow Problem With Maternity Leave

Maternity leave creates one of the sharpest income drops most people ever experience, and it arrives at exactly the moment household costs are rising with a new baby. Statutory Maternity Pay (SMP) pays 90% of average weekly earnings for the first 6 weeks, which softens the initial transition — but from week 7 onward, it drops to the lower of roughly £187 a week or 90% of average earnings, for up to a further 33 weeks (39 weeks total, unless your employer enhances this).

For many earners, that means the second phase of maternity leave brings income down to roughly a third or less of normal take-home pay. That's the point where the pension-versus-ISA question actually matters, because there isn't enough spare cash to do everything.

Case Study: Priya, 6 Months Into Maternity Leave

Priya normally takes home £2,200/month. Her employer pays enhanced SMP: full pay for 6 weeks, then the statutory rate for the remaining 33 weeks.

The gap in the second phase is roughly £1,390/month against her normal take-home pay. Over the 7.5 months of the lower rate, that's a cumulative shortfall of around £10,400 that has to come from somewhere — savings, a partner's income, or reduced spending.

What Happens to Her Pension During This Time?

Priya's employer's pension policy (fairly standard practice for many UK employers) continues to calculate its contribution based on her normal pre-leave salary throughout paid maternity leave, not her reduced SMP. So if her employer normally contributes 5% of a £33,000 salary, that contribution — roughly £137/month — keeps flowing into her pension even while her own pay has fallen to £810/month in the later phase.

Priya's own contribution, by contrast, is usually calculated as a percentage of her actual pay that period (her SMP), so it automatically shrinks in cash terms even without her doing anything — she doesn't need to actively reduce it.

This is a genuinely valuable, easy-to-miss protection: Priya doesn't need to top up her own pension contributions during the low-SMP months to keep the pension moving forward, because the employer side is doing the heavy lifting already.

So Where Should Extra Money Go — Pension or ISA?

Given the employer pension contribution is protected automatically, Priya's spare decision-making capacity is better spent on cash flow. Her real risk during months 7-15 of parental leave isn't an under-funded pension — it's running out of accessible cash to cover the roughly £1,390/month shortfall.

Using the £10,400 total shortfall figure above as a target, Priya would want roughly that amount available in an ISA or savings account before her enhanced pay period ends, ideally built up in the months before the birth rather than borrowed against future income.

and together let you model both the SMP income timeline and the savings buffer needed to bridge it.

Don't Overlook National Insurance Credits

One thing that doesn't need active management: National Insurance credits. While receiving SMP or Maternity Allowance, and later while claiming Child Benefit for a child under 12 (even if you opt out of actually receiving the payment because of the High Income Child Benefit Charge), you typically continue to receive NI credits that protect your State Pension qualifying years. This matters because the full new State Pension (£230.25/week, around £11,973/year for 2026/27) depends on a set number of qualifying years — maternity leave alone should not create a gap here, provided Child Benefit is claimed even at £0 payment.

The Bottom Line for New Parents on SMP

The pension-versus-ISA framing during maternity leave is often a false choice, because the employer side of the pension is usually protected by law and company policy regardless of what you personally decide. The genuine decision is how much cash buffer to build before the lower SMP rate kicks in, and whether to top up pension contributions further only once income has returned to normal after leave ends.