Locking in Growth: Your Complete Guide to the Best 5-Year Fixed-Rate Cash ISAs

When planning for medium-to-long-term savings goals, striking a balance between growth and security is essential. If you want to protect your capital from market volatility while locking in a guaranteed return, a 5-year fixed-rate Cash ISA is one of the most powerful tools in your financial arsenal.

By freezing your interest rate for half a decade—all completely tax-free—these accounts allow you to plan with absolute certainty.

What is a 5-Year Fixed-Rate Cash ISA?

A 5-year fixed-rate Cash ISA is a tax-wrapper savings account where your money is locked away for a strict five-year term. In exchange for committing your funds for this duration, the provider guarantees a fixed interest rate (AER) that cannot drop, no matter how the broader economic landscape or base interest rates shift.

• Tax-Free Growth: All interest earned is entirely safe from Income Tax, meaning you don’t have to worry about breaching your Personal Savings Allowance (PSA).
• The Allowance: For the current tax year, you can save or invest up to £20,000 across your ISAs.

Current Market Leaders: Top 5-Year Fixed ISAs

The 5-year fixed market features competitive offerings primarily spearheaded by challenger banks and building societies looking to secure stable, long-term deposits. Leading options include:

| Provider | Product Type | AER (Fixed) | Min. Deposit | Key Feature |
| :— | :— | :— | :— | :— |
| Shawbrook Bank | Non-Flexible | 5.25% | £1,000 | Top market rate; monthly/annual interest |
| Tandem Bank | Flexible | 5.13% | £1 | Flexible ISA allowances; low entry barrier |
| Castle Trust Bank | Non-Flexible | 5.12% | £1,000 | Interest paid on maturity |
| Close Brothers | Non-Flexible | 5.12% | £10,000 | Geared toward larger lump sums |
| Skipton Building Society | Non-Flexible | 5.00% | £1 | Trusted mutual society with low minimums |