Complaints
Financial Ombudsman Service
NS&I is covered by the Financial Ombudsman Service (FOS). This ensures that all customer disputes are dealt with equally and fairly, giving customers access to the same dispute resolution process as other financial service providers.
How to make a complaint
You can speak to our dedicated team directly. They will aim to resolve your complaint promptly and are happy to help.
Call us free from the UK:
0800 092 1286
Or write to us at:
Customer Service Team
NS&I
Sunderland
SR43 2SB
Complaints performance data
We are committed to fairness and transparency across our business. We regularly publish information about our performance, including complaints data.
The following data refers to complaints recorded about NS&I between 1 October 2025 and 31 March 2026.
| Product / Service grouping | Provision (at reporting period end date) | Intermediation (within the reporting period) | Number of complaints opened | Number of complaints closed | Percentage closed within 3 days | Percentage closed after 3 days but within 8 weeks | Percentage upheld | Main cause of complaints opened |
|---|---|---|---|---|---|---|---|---|
| Banking and credit cards | 0.27 | N/A | 13,609 | 13,299 | 80.61% | 19.14% | 53.45% | General Admin/Customer Service/Other general admin |
| Home Finance | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Insurance and pure protection | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Decumulation and pensions | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Investments | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
| Credit related | N/A | N/A | N/A | N/A | N/A | N/A | N/A | N/A |
To support our ethos of transparency, and to put the above figures into context, we are also providing the following information.
- Less than one complaint was opened per 1,000 accounts (holdings) held.
- The total number of holdings at NS&I as of 31 March 2026 was 49,865,483. Examples of NS&I holdings include individual Savings Certificates, Direct ISA accounts, Direct Saver accounts and Premium Bonds. For Premium Bonds, we deem all Bonds held under one holder's number to be one holding.
- Details of complaints data published by the Financial Ombudsman Service (FOS) can be found on the Financial Ombudsman Service website .
Historic complaints data
Complaints-historic-data - March 2024
Complaints-historic-data - September 2023