Nationwide Building Society has launched an 18 month fixed-rate savings account paying 5 per cent interest.

The new 'Member Exclusive Bond' is only available to existing Nationwide customers.

The account was unveiled alongside Nationwide's £100 'Fairer Share' payment and a £200 member switching bonus.

This is now the best rate available for a fixed-rate savings bond, beating both the top 18-month and one-year fixed-rate accounts on a deposit of £10,000.

Around 16million people will be able to get this savings account as it is only available to those who are already members of the society. 

The account can be opened online, using internet banking, in the Nationwide mobile app or in a branch.

What are the account's rules? 

To get the account, members needed to have held a Nationwide current account, savings account or mortgage account on 29 May 2025 and at the time of applying.

However, there is a catch. The maximum amount a saver can put in this account is £10,000. 

Members saving the maximum £10,000 would receive £762.50 in interest after 18 months, £150 more than they would receive over the same period in Nationwide's next highest-rate bond, a one year fix that pays 4 per cent.

This account now takes the top spot for an 18-month fixed-rate account on This is Money's best buy savings rate tables.

For members who want to stash more than the £10,000 cap in a fixed-rate bond, the next best deal is Oxbury Bank's 18-month bond which pays 4.45 per cent. 

While the best one year-fixed rate bond pays 4.44 per cent and is offered by Castle Trust Bank. A saver putting £10,000 in this account would earn £453 at the end of the term. 

Savers won't be able to withdraw money from the Nationwide account until the 18-month term ends. Interest is paid annually on the anniversary of account opening and at maturity. 

One savings expert thinks the 18-month bond looks attractive despite the catch of £10,000 being the maximum deposit limit.

Andrew Hagger, personal finance expert and founder of Money Comms said: 'Eighteen months at 5 per cent is an excellent deal it's 0.55 per cent higher than the current best buy from Oxbury Bank at 4.45 per cent. 

'As a Nationwide member I would seriously consider this, even though the maximum you can save in this exclusive bond is £10,000. 

'Despite this I'm sure there will be no shortage of takers.'