Cynergy Bank Savings Accounts: Rates, Bonus Trap and Verdict

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Cynergy Bank’s one-year Fixed Rate Bond pays 5.05% AER, read from Cynergy’s own rates page on 7 October 2026, and it is now the only competitive thing the bank sells to a new customer. The Online Easy Access Account — the bonus-inflated headline that put Cynergy on every best-buy table — now carries the line “available for our existing customers only”. If you do not already hold one, you cannot open one.

That one-year rate beats every other term Cynergy offers, including the five-year at 4.30%. The curve is not merely flat, it is inverted, and sharply: locking money away for five times as long pays you 75 basis points less.

There is a second structure to understand before comparing Cynergy with anyone else. Every bond and fixed cash ISA is published at two rates: an advertised rate for new money and a loyalty rate, up to 0.85 percentage points higher, available only when a maturing Cynergy account funds it. On the two and three-year bonds the gap is 80 and 85 basis points — 4.20% advertised against 5.00% and 5.05% loyalty. Any single-figure quote for a Cynergy bond is therefore telling you only half the story, and quite possibly the wrong half.

The easy access account, and why it still matters

Cynergy’s easy access pricing is now a closed book, but it is worth reading if you are already in it. The account pays 4.15% AER with a bonus for the first twelve months and 2.15% AER without it. Both figures are Cynergy’s own: the bank used to publish only the headline, leaving the underlying rate to be worked out by subtraction, and it now prints both side by side. That is a straightforward improvement in disclosure and it confirms the two-point gap.

So an existing customer who opened the account on its old 4.55% headline should treat month eleven as a deadline. Once the bonus falls away the money is sitting at 2.15%, which is behind Close Brothers’ unconditional 3.85% and barely ahead of Aldermore’s 2.25%. Because the account is closed to new customers, you also cannot reset the clock by opening a fresh one — the usual bonus-hopping move is off the table here.

• Status: closed to new customers
• With bonus: 4.15% AER, first 12 months
• Without bonus: 2.15% AER, published by Cynergy
• Withdrawals: unlimited and free, no notice, no rate penalty

The Online ISA at 4.15% AER variable is still open, takes £1 and accepts transfers in. It now pays exactly what the easy access account pays with its bonus attached, tax-free rather than taxable, which makes it the more sensible home for anyone near their personal savings allowance.

An inverted bond ladder, and two rates for every rung

Minimum £1,000, maximum £1,000,000, with a 14-day funding window and no withdrawals once the term is underway. Interest is paid into the bond and cannot be paid away, which rules the product out for anyone drawing an income from their capital.

The rates, advertised first and loyalty second:

• 6 months — 4.57% / 4.58%
• 1 year — 5.05% / 5.06%
• 15 months — 4.40% / 4.65%
• 18 months — 4.40% / 4.65%
• 2 years — 4.20% / 5.00%
• 3 years — 4.20% / 5.05%
• 4 years — 4.25% / 4.26%
• 5 years — 4.30% / 4.35%

Read the advertised column on its own and the conclusion is blunt: take the one year at 5.05% and nothing else. The 15 and 18-month bonds pay 65 basis points less than the one-year for holding your money longer, and the two and three-year pay 85 less. There is no term at which a new saver is rewarded for committing beyond twelve months.

The loyalty column changes the shape completely — 5.00% at two years and 5.05% at three make the ladder behave normally — but those rates need a maturing Cynergy account to fund them, so they are a reason to stay rather than a reason to arrive. Judge the bank on the advertised column, then treat loyalty as what it is: a retention offer you may qualify for in a year.

Cash ISAs

The one-year Fixed Rate Cash ISA is 4.05% AER advertised and 4.75% loyalty, with a £500 minimum and the £20,000 subscription cap. The 70-point gap is the widest in the range. Closing early costs 180 days’ loss of interest, and it is not a flexible ISA — money taken out cannot be replaced without using fresh allowance.

Notice accounts

Three terms, all with a £500 minimum: 35 day at 4.12%, 95 day at 4.15% and 120 day at 4.18% AER. These were the weakest part of this page when it was last written, quoted from a third-party table and flagged as indicative. They are now read from Cynergy’s own rates page, and the 120-day account at 4.18% is the best rate Cynergy will pay you without locking the money away at all.

Awards, complaint volumes and the loyalty catch

Cynergy carries better independent recognition than its size suggests. The Defaqto Banking Award 2026 for Instant Access Cash ISAs is a consistency measure rather than a snapshot: a product has to sit in the top fifteen for ten of twelve months to qualify, and only 29 products out of 2,114 assessed made the cut across all categories. It is also a Which? Recommended Provider.

On complaints, the Financial Ombudsman Service recorded 83 new cases against Cynergy for the period 1 July 2025 to 31 March 2026 — the second-lowest volume of the five providers in this cluster. Per-firm uphold percentages are published only inside an FOS spreadsheet we could not access, so the proportion of those cases decided in the customer’s favour is unverified.

The loyalty structure deserves one more line, because it has grown since this page was first written. It is no longer a footnote about maturing bonds: it is a second published rate on every bond and every fixed ISA, and on the two and three-year bonds it is worth more than the entire gap between Cynergy and the best rate in this comparison. New money is, by design, offered the worse of the two.

Living with a branchless bank

Cynergy is an online operation: accounts are opened and run through the website or app, and the terms say plainly that the accounts are “not suitable for savers who are unable to use Online Banking”. Deposits and withdrawals move through a nominated UK current account. Reported friction points cluster around slow telephone support at peak times and app-based authentication that some customers find fiddly.

Eligibility is straightforward — you must be 18 or over and UK resident for tax purposes. Existing customers get a Fast Track Apply route inside online banking, which removes most of the re-keying when opening a second or third account, and is also how the loyalty rates are reached.

Deposits are protected by the FSCS up to £120,000 per eligible depositor, and Cynergy states that each holder of a joint account is entitled to compensation up to that limit. One correction to what this page said before: Cynergy does not publish a “£240,000 joint” figure, nor an explicit statement that its licence is unshared, so neither is asserted here. If you hold money with more than one brand, check the licence yourself on the FSCS register before assuming the limits stack.

Figures were taken from each provider's own published terms on 7 October 2026. Variable rates can change at any time — confirm the current rate with the provider before applying.