Premium Bonds vs a Marcus by Goldman Sachs Easy Access Account for a 20,000 GBP Emergency Fund

Each individual £1 bond inside a £20,000 Premium Bonds holding faces monthly odds of roughly 22,000 to 1 for a prize. Move that same sum into a Marcus by Goldman Sachs online savings account and next month’s interest can be worked out to the penny. Everything about the comparison flows from that gap between a fixed calculation and a monthly draw, once prizes, tax and access rules are set beside the headline rates.

The prize fund rate is a pool figure

NS&I sets a prize fund rate. As of the most recent revision, it is 4.00%. The figure describes the total prize pot divided across all eligible bonds, so it is an average across the pool instead of a personal rate attached to each saver’s holding.

A saver holding the maximum £50,000 will tend closer to that 4.00% figure over a long enough period. A £20,000 holding gives a choppier result because fewer bonds are entered in each monthly draw. The smaller holding leaves more of the annual outcome resting on whether a larger prize lands in that account.

Run £20,000 through the arithmetic and the median annual return sits below the advertised rate. Many £20,000 holders will receive a sequence of £25 and £50 prizes, perhaps with an occasional £100 prize, and finish the year somewhere around 3% to 3.5% in effective terms.

The two monthly £1 million jackpots, plus the £100,000 and £50,000 prize tiers, lift the average for the full prize pool. Typical holders can still finish below that pool average, because part of the expected return is carried by rare outcomes.

Premium Bonds appeal because the payoff has a lottery shape. Every £1 bond has a live chance at £1 million each month, and some savers accept a lower likely return in exchange for that possibility.

Tax changes the Marcus figure

Premium Bond prizes are entirely free of UK income tax. Marcus interest is taxable, and the Personal Savings Allowance determines how much of that interest is sheltered.

A basic-rate taxpayer gets £1,000 of savings interest tax-free each year. A higher-rate taxpayer gets £500. Additional-rate taxpayers get no Personal Savings Allowance.

Take £20,000 in a Marcus account paying 3.75%. Over a year, that produces £750 of interest. A basic-rate taxpayer keeps the full £750 because it fits inside the £1,000 allowance.

A higher-rate taxpayer breaches the £500 allowance and pays 40% on the £250 excess, losing £100. An additional-rate taxpayer pays 45% on the full £750, losing £337.50.

Once the tax bill is folded in, the ranking can flip for the highest earners. An additional-rate taxpayer weighing an illustrative tax-free 3.2% median result from Premium Bonds is really comparing it against a Marcus rate of 3.75% that falls to about 2.06% after tax. At that point the prize draw can win on likely after-tax return as well as on the absence of any tax charge.

If HMRC has taxed savings interest through an adjusted tax code and the numbers appear wrong, the reclaim route runs through a P800 calculation or a self-assessment adjustment. Banks report interest to HMRC automatically each year. Marcus reports interest; NS&I prizes never appear because there is no taxable interest to report.

Access speed in a real emergency

An emergency fund earns its name when the boiler fails or a car fails its MOT with a £900 repair bill. The practical test is how fast the money can leave the account and become spendable.

Marcus processes withdrawals to a linked nominated account. Transfers typically clear the same working day or the next working day through Faster Payments. The standard easy access product has no penalty, no notice period and no cap on the number of withdrawals. A saver logs in, requests the transfer and usually has spendable cash within hours.

NS&I allows Premium Bonds to be cashed in online, with payment usually reaching the bank account within three working days. That lag is the practical price attached to the prize structure. Three working days can matter when a tradesman wants payment or a card payment is due. Both products are liquid in broad savings terms, though only one of them is genuinely built for a Friday-evening cash problem before the weekend.

FSCS and the Treasury guarantee

Marcus deposits are protected up to £85,000 per person by the Financial Services Compensation Scheme, held under the Goldman Sachs International Bank licence. NS&I is backed directly by HM Treasury, so 100% of the holding is guaranteed with no upper cap. On £20,000, both protections leave the saver comfortably covered, and the distinction only bites above the £85,000 threshold.

What the cash does while it waits

An emergency fund has a plain job: it must be liquid on the day it is needed. That clashes with the urge to chase the top of the best-buy tables, where higher easy access rates may sit beside fixed-term or notice products that lock up money for 30, 60 or 95 days. A 95-day notice account paying 4.5% cannot cover an emergency that needs payment today.

The £20,000 decision often works better as a split. One example holds £8,000 in Marcus to cover three to four months of essential outgoings, leaving £12,000 in Premium Bonds for the tax-free draw and the comfort of guaranteed capital. That smaller cash slice handles the fast bills such as the boiler or the MOT, while the larger bond holding sits ready for bigger shocks, where waiting three working days for the money is no real hardship.

Behaviour matters too. Some savers are tempted to spend cash that produces a visible monthly interest line. Premium Bonds can feel easier to leave alone because returns arrive as prizes instead of income. That quirk can help or hurt depending on how the saver treats money set aside for emergencies.

The rate environment has shifted this calculation several times. When the Bank of England base rate was near zero, easy access accounts paid very little and the Premium Bond prize fund looked comparatively generous. As the base rate climbed past 5% and then eased back, the ranking changed again. The relationship between the NS&I prize fund rate and the best easy access rate is variable, so the stronger option in April may have lost its edge by October.

Reinvestment also affects the annual result. Marcus interest can compound inside the account, so the balance grows and future interest is paid on a higher sum. Premium Bond prizes can be reinvested automatically into new bonds up to the £50,000 ceiling, giving winnings their own entries in later draws. Both products let gains feed into future returns, one through compounding interest and the other through extra prize entries.

Where a £20,000 decision lands

For a basic-rate taxpayer whose Marcus interest stays inside the £1,000 allowance, the stated Marcus rate and same-day access create a clean case for the easy access account. For an additional-rate taxpayer with a fully used allowance and no urgent need for the whole balance, Premium Bonds have a genuine mathematical case once tax is included.

On £20,000, the difficult figure is the portion that might need to move inside a few hours. A balance sized around that need fits the same-day account; anything beyond it can be weighed against the tax-free draw. The harder question, and one the headline rates never answer, is how confidently a saver can predict which future emergency will need cash before a redemption has time to clear.