ISA promotions, boosted rates and transfer offers

ISA promotions come in two main shapes: a boosted interest rate that pays you extra for a fixed period, and a cash bonus paid into your account as a lump sum. A boosted rate is a set percentage added on top of the provider's standard ISA rate for a promotional window, commonly 90 calendar days, after which the rate reverts to the standard one¹. A cash bonus works differently: the provider pays money into your ISA, usually within weeks of your first payment, and that money counts towards your annual ISA allowance².

These offers are real, but they come with conditions that decide whether they are worth having. The two most common are a new-customer rule, which can exclude anyone who has ever held an account with the provider, and a fair usage period, during which closing the account can let the provider take the bonus back¹. This page explains how the promotions documented by providers actually work: how long boosts last, who qualifies, how promo codes are claimed, how the interest is paid, and where the protections stop.

How ISA promotions work: boosted rates and cash bonuses

A boosted rate does not replace the provider's standard rate; it sits on top of it. Chip's terms describe this precisely: the boosted rate is applied to the balance you hold in your Cash ISA account each day, and the interest it earns is paid monthly⁸. The boost is a fixed percentage addition, so if the provider's standard rate moves, your total rate moves with it, but the boost itself stays the same. Chip's own guidance gives this example structure: if the underlying Cash ISA rate changes, your AER changes accordingly, while the boost percentage remains fixed⁹.

A cash bonus is a different animal. Shepherds Friendly's ISA Boost, for example, is a payment made by the provider into your Investment ISA or Junior ISA, equal to your first monthly Direct Debit payment if you open the plan that way, up to a value of £100². The provider publishes a tiered table for the offer: a £10 first monthly payment earns a £10 boost, £20 earns £20, £30 earns £30, £40 earns £40 and £50 earns £50². The boost is paid within 30 days of your first monthly premium being received into the ISA².

The two types suit different savers. A boosted rate rewards a lump sum sitting in the account: the bigger the balance and the longer the boost, the more it pays. A cash bonus rewards starting a regular saving habit, because its size is tied to the first monthly payment rather than to the balance. Neither is free money in the sense of being unconditional: both carry eligibility rules and, in the documented cases, a fair usage period during which the provider can claw the money back¹.

Referral offers are a third variant, worth knowing about because they can stack with other promotions. Chip's referral terms give referees a percentage boost on top of the existing Instant Access rate for 90 days¹⁰, and the provider confirms the referral code can be shared more than once¹¹. Shepherds Friendly, by contrast, states its ISA Boost cannot be claimed in conjunction with other offers such as cashback and voucher codes², so stacking is a provider-by-provider question rather than a general rule.

How long a boosted rate lasts: from 90 days to 6 months, and sometimes a year

Ninety calendar days is the standard length in the documented offers. Chip's ISASEASON promotion applied its boost for 90 calendar days, after which the rate reverted to the standard Chip Cash ISA rate¹. The same 90-day pattern appears in the February 2025 boosted rate promotion³, in the Instant Access loyalty rate boost, which the terms state lasts for 90 days¹², and in the referral boost for referees¹⁰.

Longer windows exist. Chip's terms for one boosted rate promotion state the boost is applied for 180 calendar days once the eligibility conditions are met¹³, and a separate CASHISA12 promotion ran for 365 calendar days⁵. When providers describe these periods in months, they define the terms precisely in their promotion terms: "3 months" corresponds to 90 calendar days, "6 months" to 180 calendar days, "9 months" to 270 calendar days, and "12 months" to 365 days³.

Two practical points follow from the fixed length. First, the clock usually starts when you meet the conditions, not when you first see the advert, so the deposit date matters. Second, the end of the boost is not the end of the account: the money stays where it is and simply earns the standard rate, which may be much less. A saver who chose the account for the boost needs to check the rate again when the boost ends, and remember that moving the money elsewhere means using the ISA transfer process rather than withdrawing, to keep the tax-free status intact¹⁴.

Who qualifies: new customers only, and how narrowly that is defined

The new-customer rule is the gate on most of these offers, and providers define it strictly. Chip's ISASEASON promotion was available only to new customers who had never previously held a Chip account, and the provider's own definition is blunt: a new customer is someone who has never previously held a Chip account¹. There is no partial credit for having closed an account years ago.

Shepherds Friendly's exclusions go further and are worth reading in full, because they show how widely a provider can draw the net:

• You are not eligible if you currently hold an Investment ISA or Junior ISA with Shepherds Friendly²
• You are not eligible if you previously held one and have since cancelled or closed the plan²
• You can only hold one Investment ISA with the provider; multiple applications are merged and the ISA Boost is not paid in that instance²
• The boost can only be used once per person, although each child counts as an individual person for Junior ISA purposes²

The lesson for a reader is to check the eligibility list before opening anything, not after. An account opened in good faith can be reclassified or merged under these clauses, and the promotion simply does not get paid².

Transfers interact with eligibility in a specific way. Chip states across several of its boosted rate promotions that pending transfers do not count towards the minimum £1 balance¹. In other words, money that is on its way from another ISA provider, but has not yet arrived, does not start the boost. Since ISA transfers take time to complete, a saver transferring in to qualify for a promotion needs the money to land before any deadline in the terms. The rules on how long an ISA transfer takes and on partial transfers matter here: since April 2024, legislation has allowed the partial transfer of subscriptions made in the current tax year²⁰, which gives more flexibility over how much money is moved.

How to claim a boosted rate with a promotion code

Promo-code offers follow a sequence, and the sequence has deadlines built into it. Chip's ISASEASON promotion is the documented example, and its steps are typical of app-based providers¹:

1. Download the Chip app
2. Set up your account
3. Go to Profile, then Promos & Referrals, and enter the code ISASEASON
4. Open a Chip Cash ISA account
5. Deposit and hold a balance of at least £1

The deadlines are the part people miss. The code had to be entered within 14 calendar days of downloading the app, and the £1 minimum balance had to be deposited and held within 14 calendar days of entering the promo code¹. The offer also required at least version 4.56.0 of the app to participate¹. Other Chip offers used the same route with different codes: the ISA6BOOST code was entered via the same Profile and Promos & Referrals screen, followed by opening a Cash ISA and holding at least £1⁹, and the 3MONTHISA code followed the identical path²¹.

Claiming a boosted rate is a sequence with time limits at each step.

If something goes wrong, the documented route is the provider's own support. Chip directs customers to the in-app chat, in the Contact us section on the Profile tab, or by email to hello@getchip.uk¹. For wider problems with an ISA provider, including a promotion that was promised and not delivered, the route is the provider's complaints process and then the Financial Ombudsman Service.

Cash bonuses paid into an ISA count towards your £20,000 allowance

The annual ISA allowance is £20,000⁶, and a bonus paid into an ISA by a provider uses that allowance just like your own money does. Shepherds Friendly states this plainly in its ISA Boost terms: the boost is paid directly into your Investment ISA or Junior ISA, and it counts towards your annual ISA allowance usage². A £100 bonus therefore leaves you £100 less of your own allowance to subscribe that tax year.

This is easy to overlook because the money arrives from the provider, not from your bank account. But the subscription records treat it identically. If you are close to your allowance in the relevant tax year, a bonus can push a further payment of your own money over the limit, and money subscribed in excess of the allowance loses its tax-free status. The rules on invalid subscriptions and on how the allowance works cover what happens next.

The allowance itself has been the subject of policy debate. The Building Societies Association reported in October 2025 on a proposed cut in the annual Cash ISA limit from £20,000 to £5,000²², and the total annual ISA allowance is set to remain frozen at £20,000 until 2030. Which? has also covered how savers have aimed to maximise their annual £20,000 ISA allowance in response to changes in the wider tax rules⁶. Nothing in the documented material changes the £20,000 figure today, but a reader planning subscriptions several years ahead should check the current position, because the debate is live.

One point of reassurance: transferring money between ISAs does not use the allowance again. Money saved in previous years can be shifted from ISA to ISA, switching provider, without losing the tax breaks¹⁴, and the transfer rules confirm that a transfer is not a new subscription. The allowance question only bites on new money going in, including provider bonuses.

How boosted interest is paid

Boosted interest in the documented offers is paid monthly, not accumulated and paid at the end. Chip's terms are consistent on this across every promotion documented: the interest earned from the boosted rate is paid monthly as part of the regular monthly interest payment, which occurs on the fourth business day of each month⁸. The same rule appears in the referral promotion terms¹⁰ and in the CASHISA12 promotion terms⁵.

The mechanics are that the boost is applied daily and the interest is paid monthly. Chip's guidance states the boosted rate is applied daily to your balance and the interest is paid monthly²⁶. This means the boost accrues through the month on whatever balance is actually in the account, so withdrawing money mid-month reduces the amount the boost is applied to, and the payment lands on a predictable date rather than being held to the end of the promotional window.

For a saver, the practical effect is that a boosted rate produces visible interest payments from the first month. It also means the final month's boost is paid in the month it is earned, rather than being deferred. If a promotion ends mid-month, the boost applies up to its end date and the standard rate applies after, with the interest payment reflecting the split. The tax treatment of ISA interest is straightforward: interest earned inside an ISA, including from a boost, is not subject to income tax on withdrawal.

Fair usage rules and when a bonus can be taken back

A cash bonus is conditional, and the condition is usually a fair usage period. Shepherds Friendly's ISA Boost carries a 12-month fair usage period, which starts on the date the first payment is made into the Stocks and Shares ISA². Closing the plan during that period is defined as a breach of the fair usage policy², and the consequence is explicit: if a breach is found, Shepherds Friendly reserves the right to deduct the value of the ISA Boost from the Investment ISA².

A cash bonus is tied to a fair usage period; closing the plan inside it can trigger a clawback.

Boosted rates have their own version of the same principle. Chip reserves the right to disqualify any participant or promo code if there is any suspicion of deception, fraudulent activity or abuse, and to modify or terminate the promotion at any time without notice¹. The same right appears in the boosted rate promotion terms⁹. Shepherds Friendly likewise reserves the right to withdraw its offer at any time².

This is not unique to ISAs. The Lifetime ISA carries the sharpest version of a government clawback: withdrawing early for purposes other than a first home or retirement returns the government bonus element, including any interest or growth on it, to the government, and attracts a charge²⁷. The Lifetime ISA withdrawal charge is covered in detail elsewhere on the site. The Help to Buy ISA bonus has a timing condition of its own: because the bonus is only paid on completion, it cannot be used as an exchange deposit, so a buyer needs other money for that stage²⁸, and the scheme is only available for first time buyers²⁹.

Junior ISAs: one bonus, not two

Junior ISAs add a wrinkle to promotion rules, because the account changes hands in effect at 18. Junior ISAs automatically turn into an adult ISA when the child turns 18, as GOV.UK states³⁰, and NS&I describes the same mechanics from the provider side: on the child's 18th birthday the money is automatically transferred into an adult cash ISA³¹. The legislation underpinning Junior ISAs also allows transfers between cash and stocks and shares Junior ISA accounts for the same named child, with current-year subscriptions counting towards the child's overall subscription limit for that year³⁰.

The promotion consequence is documented in Shepherds Friendly's terms: if an ISA boost is paid into a Junior ISA which then matures, the same member cannot receive an ISA boost into an adult stocks and shares ISA². The once-per-person rule follows the person through the transition from child to adult account. However, the terms also state that with regard to a Junior ISA, each child is classified as an individual person², which matters for families: a boost paid into one child's Junior ISA does not block a boost for a different child.

Age rules frame the picture. Adult cash ISAs are available to children from the age of 16, and eligible children can hold both a Junior cash ISA and an adult cash ISA³³, while a Junior ISA itself is for children under 18³⁴. Gifting money to loved ones under the age of 18 is a recognised route for inheritance tax planning³⁴, and a Junior ISA bonus can form part of that. The pages on Junior ISAs, on what happens to a Junior ISA at 18 and on the Junior ISA allowance cover the mechanics in full.

Where the protection stops

ISA promotions are marketing offers, not contractual rights in the way a fixed rate is, and the terms say so. Chip reserves the right to modify or terminate the Boosted Rate Promotion at any time without notice⁹, and to disqualify any participant or promo code on suspicion of deception, fraudulent activity or abuse¹. Shepherds Friendly reserves the right to withdraw its ISA Boost offer at any time². A reader who signs up should assume the offer can change, and keep a copy of the terms they signed up under.

The boost itself is not a guaranteed total rate. Because a boosted rate is a fixed addition to a variable standard rate, a provider can cut the standard rate during the promotional period and the saver's total rate falls with it, as Chip's own terms describe⁹. A saver comparing offers should therefore look at the standard rate that follows the boost, not just the headline addition, and the comparison of fixed rate versus easy access cash ISAs sets out that trade-off.

Transfers carry their own risks, and a promotion that requires transferring an ISA in should be planned around them. Which? has documented what happens when a stocks and shares ISA transfer goes wrong³⁵, and the Financial Ombudsman Service has published a case study involving an unexpected withdrawal charge when transferring money between different ISA types³⁶. Not all providers accept every kind of transfer: Which? notes of Additional Permitted Subscriptions, the inherited ISA allowance, that not all ISA providers let people use them, so you need to check with your provider that they accept these extra deposits before transferring³⁷. Money can also be transferred from a cash ISA or stocks and shares ISA into an innovative finance ISA, as Which? explains³⁸, but that is a different risk profile altogether, covered in Innovative Finance ISAs.

Where a promotion goes wrong, the escalation path is the provider first, then the Financial Ombudsman Service, which handles complaints about ISA providers³⁶. The page on complaining about an ISA provider sets out the process, and how your ISA is protected covers the deposit protection that sits underneath the account itself, which is unaffected by any promotion.