Santander Stocks and Shares ISA: £100 cashback through TopCashback
Open a new Santander Stocks and Shares ISA through TopCashback, invest £100 and get £100 cashback. Here is how to qualify, what can go wrong and how new TopCashback members can add a £10 joining bonus.
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The short answer: TopCashback is paying £100 cashback when you open a new Santander Stocks and Shares ISA and invest at least £100. You keep your £100 investment, so the cashback is effectively a 100% bonus on what you put in. The catch is that the money must stay invested for 90 days, and investments can go down as well as up.
Capital at risk. The value of investments can go down as well as up, so you could get back less than you put in. Tax treatment depends on your circumstances and can change. The £100 cashback does not protect you from investment losses or fees.
What you get
| Detail | What it means |
|---|---|
| Cashback | £100, paid by TopCashback, not Santander |
| Minimum investment | £100 lump sum, or £20 a month |
| Who qualifies | New Santander Stocks and Shares ISA customers, 18+, UK resident for tax |
| Holding period | Your money must stay invested for at least 90 days |
| Checked | 31 October 2026, against TopCashback’s offer terms |
Cashback rates change often, so check the amount on TopCashback’s Santander page before you apply.
How to claim the £100
- Join TopCashback if you are not a member yet. New members joining through our TopCashback invitation can also earn a £10 joining bonus (see below).
- Click through to Santander from TopCashback’s Santander Stocks and Shares ISA page. Do not go to Santander directly or through a comparison site, or the cashback will not track.
- Open the ISA and invest in at least one fund in the same session. This is the rule that trips most people up: money left as cash in the ISA does not count, and the initial investment has to happen while you are still in the application.
- Leave the money invested for 90 days. Withdrawing, switching out or cancelling a monthly direct debit during that time means no cashback.
- Check your TopCashback earnings page. Cashback should appear within 7 days. If it does not, submit a missing cashback claim within 100 days.
You do not need a Santander current account to apply. If you are new to Santander, your login details arrive by post afterwards.
How fast does it pay?
Members on Reddit’s r/beermoneyuk report that the cashback tracked within minutes, and several said it became payable in around 8 days. Others saw an expected date about three months away, which matches the 90-day holding rule. Plan on waiting the full 90 days, and treat anything faster as a bonus.
Common problems
- “We need more time to check your details.” Some applicants get this screen and cannot invest straight away, which clashes with the same-session rule. If it happens to you, keep a screenshot, invest as soon as you can and contact TopCashback if the cashback does not track. Readers who raised this with TopCashback were told it would be checked with Santander.
- You already have a Santander ISA. Existing Stocks and Shares ISA customers, top-ups and ISA transfers from another provider do not qualify. Having a Santander current or savings account does not stop you.
- You have used your ISA allowance. You can pay in up to £20,000 a tax year across all your ISAs. The £100 counts towards it, so check what you have left before you apply.
- You opened more than one. TopCashback only pays on the first Stocks and Shares ISA you open through it.
Which fund should you pick?
The offer only needs you to invest in at least one fund. Santander lets you choose different risk levels, and readers who picked the lowest-risk option still had the cashback tracked. A lower-risk fund will not remove the risk of losing money, but it usually moves less over a short period like 90 days. Check the platform and fund charges before you invest, because fees come out of your pot.
Add a £10 TopCashback joining bonus
If you are new to TopCashback, join through our TopCashback invitation before you apply. New members joining between 31 October and 9 November 2026 get a £10 sign-up bonus once they have earned £10 of approved cashback within 180 days. Santander is not on TopCashback’s list of brands excluded from that threshold, so the ISA cashback should count once it is approved.
That makes the total £110 for a new member: £100 from the ISA offer and £10 joining bonus, on top of the £100 you invested. We earn a referral reward if you join through our link, at no cost to you.
Is it worth it?
For £100 left invested for three months, a £100 reward is one of the best cashback offers around. It makes most sense if you were thinking about a Stocks and Shares ISA anyway, or you are comfortable with a small amount being invested and possibly falling in value. If you cannot afford to lose any of the £100, or you need the money within 90 days, skip it.
For more ways to earn from new accounts, see our bank and investing sign-up bonuses, and read how cashback works to understand tracking and payout times.