HMRC has apologised after tens of thousands of people wanting to top up their state pension on 5 April, the last day of a special window to fill National Insurance (NI) gaps between 2006 and 2018, were wrongly told that the deadline had passed.
Saturday, 5 April had been the last chance for customers to buy NI credits dating back to 2006 and boost their state pension. Usually it’s only possible to buy National Insurance credits for the past six tax years.
There had been a huge amount of publicity about the special window and the deadline, and long wait times to get through to the Department for Work and Pensions (DWP) on the phone to discuss buying the NI credits.
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However, in an embarrassing blunder, HMRC took the online service down a day early by mistake, affecting thousands of people who wanted to make payments between 2006 and 2021.
A spokesperson said: “We’re sorry that customers were unable to use our online service on Saturday to top up National Insurance contributions for years prior to 2021. We will contact anyone affected directly about the payments they wanted to make to ensure they don’t miss out.”
About 21,000 customers who logged onto the webpage on 5 April and had payable gaps between 2006-07 and 2020-21 will be contacted.
What happened to the online state pension top-up service?
MoneyWeek understands that the online state pension service to make payments between tax years 2006-07 and 2020-21 was unintentionally taken offline a day earlier than planned.
HMRC is able to identify those who visited the website on 5 April 2025, and is currently assessing the most effective way to contact them.
Customers were still able to make payments for years as far back as 2021 and the DWP’s separate call back service was working as normal.
The online call back request service was launched by the DWP at the end of February after its phone lines were overwhelmed by people wanting to check their NI record and potentially buy credits to boost their pension.
The 5 April deadline created a “high number of calls” to the DWP’s helpline, which resulted in “long wait times”, according to the Future Pension Centre.
Under the new rules announced in February, people could still buy credits going back to 2006 as long as they logged a call back request by 5 April.
If you’ve logged a call back request, the DWP will phone you at a later date to discuss payment of the voluntary NI contributions. This will normally be within eight weeks of submitting a request.
The DWP will prioritise customers who have already reached state pension age, then those within 12 months of reaching state pension age. Remaining cases will be dealt with according to the date they submitted a call back request.
A DWP spokesperson said: “We introduced an online service for individuals to register their interest and request a call back to ensure that everyone had the opportunity to boost their state pension.
“We have doubled the number of staff to process call back requests alongside sending SMS messages to alert individuals the day before we are due to call them to boost numbers answering the phone and processing rates.”
HMRC will get in touch with those people who saw an incorrect message that the deadline had passed.
MoneyWeek understands there is no need to contact DWP or HMRC.
How many people managed to top up their state pension?
The taxman told MoneyWeek last week that more than 120,000 people had so far topped up more than 260,000 years, worth £153 million.
The average online top-up payment was £1,893, HMRC said. The largest weekly state pension increase by purchasing extra NI credits was £119.31.
While under normal rules you can usually only fill gaps in NI contributions for the past six years, under a special concession, the government let people also claim back to between April 2006 and April 2018. It meant you could boost your state pension by thousands of pounds.
The allowance was meant to end in April 2023 but the DWP struggled to cope with demand and its phone lines became jammed so the deadline was extended to July 2023, and then again to 5 April 2025.
It means that since 6 April 2025 – unless you logged a call back request beforehand, or tried to top up on 5 April but were wrongly told the deadline had passed – you will only be able to make voluntary NI contributions for the previous six tax years.
Steve Webb, partner at pension consultants LCP and a former pensions minister, said that for many people a state pension top-up will be “excellent value”, but for some people topping up would be of little or no value.
You need a minimum of 35 years of NI contributions to get the full new state pension payment, and at least 10 years to qualify for any state pension.
Having 35 years can be tricky to achieve if you have taken time off to care for children or elderly relatives or if you have taken a career break.
Purchasing NI credits can "buy extra years", boosting the amount of state pension you get.
After the 5 April 2025 deadline, you will only be allowed to claim back for six years of NI credits.
Those wishing to pay for previous years are currently charged £15.85 per week or £824.20 to fill a full historic gap year. However, a few of the tax years have a different cost. If you're topping up the 2023/24 tax year, it’s £907.40, while the 2020/21 and 2021/22 tax years are about £25 cheaper.
Buying one year will typically add 1/35 of the full state pension rate or just over £300 per year.
“For individuals with multiple gaps in their NI records, the potential long-term benefits are significant,” says Kirsty Anderson, retirement specialist at Quilter.
“Even topping up a single year would be recouped within a few years of retirement.”
Ross Lacey, director at Fairview Financial Management, adds: "In our experience, it's worth everyone looking at their projected state pension and if it seems unlikely that they'll have the maximum available, to do some analysis and enquire about topping up or paying for part years.
"Generally, it takes around three years of receiving your state pension to 'pay back' the amount it cost to buy the extra years."
Topping up your state pension is not going to work for everyone. Reasons not to top up may include being young and in work, being in poor health, or you're eligible for Pension Credit.
Alice Haine, personal finance analyst at the investment service Bestinvest, says plugging gaps can be quite an expensive process, so it is important to assess whether you actually need to buy back any missing years.
“This will depend on how many more years you plan to work and whether you are eligible for NI tax credits which fill the gaps, such as those who have been sick, were unemployed or took time out to raise a family or care for elderly relations,” she says.
For example, specified adult childcare credits can be claimed for free if you are caring for a family member, and their parents are earning their own credits. This often applies to grandparents who have retired but are under the state pension age and need a state pension top-up.
Can expats top up a UK state pension?
UK expats living overseas and foreign residents who worked in Britain for at least three years can also buy NI credits and top up their state pension.
James Green, director of deVere Europe, a financial adviser firm, says that while the UK state pension may have fallen off the radar for expats who have spent years working abroad, buying extra credits “could make a substantial difference to pension outcomes”.
He comments: “For many UK nationals overseas, the state pension has become a forgotten asset. But it shouldn't be. It offers long-term, reliable income — and is often inflation-linked — and can make a real difference to financial freedom in retirement.”
Meanwhile, foreign residents who worked in Britain for three years or more can top up their National Insurance record. For example, if they only worked in the country for five years, they could buy another five years of credits to ensure they receive a UK state pension.
Ten qualifying years of NI payments would entitle them to an annual state pension of about £3,286 for life, which may rise each year depending on the country they retire in.
Foreign residents could buy more credits so they have 35 years, to give them the full new state pension.
How to top up your state pension
Before April 2023, the only way to purchase extra NI credits was by calling the Future Pension Centre at the DWP to find out about filling gaps and then phone HMRC to get a "code" to make sure their payment is correctly allocated.
Much of this can now be done online though.
You can use HMRC’s state pension forecast tool to see how much you are due based on your age and if there are any NI gaps you can fill.
You can also check your National Insurance record through your Personal Tax Account, or on the HMRC app, where you can take a survey to assess your suitability to pay online.
Haine adds: “Calculating whether to top up can be confusing though and ultimately there is no point paying for more years than you need because you won’t get that money back.
"This is why, for some people, calling the government’s Future Pension Service to double check how many years they can buy and whether voluntary contributions really will add to their state pension may be key."
How much is the state pension worth?
The full new state pension is worth £230.25 a week (£11,973 a year), following a 4.1% rise this month, thanks to the triple lock. It was previously worth £221.20 a week (£11,502 a year).
The new state pension is paid to men who were born after 1951 and women born after 1953 who have at least 35 years of NI contributions.
The full basic state pension is £176.45 per week, or £9,175 a year.
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