MoneyHMRCA taxpayer raised concerns as their situation was changingNicholas Dawson07:06, 02 Jun 2026HMRC has explained the rules around tax on pensions. The group explained when it may make changes to your tax record, as well as some key timelines to note. The group also set out how certain taxpayers can reclaim some money from the taxman.‌A taxpayer posed a question to the authority over social media regarding pension contributions into a SIPP. A SIPP, or self-invested personal pension, is a pension pot where the individual decides for themselves where their money is invested, creating a tailored portfolio. The taxpayer wanted to understand the rules they had submitted a self-assessment over the past few days, with details of their SIPP contributions for the 2025/2026 tax year. They were keen to find out whether they could make changes to their tax return.‌They also enquired: "Can I check the amount I enter in my submission for pensions is my contribution + basic rate tax refund via provider (from HMRC)?"‌State Pensioners to face major tax changeProcessing timesIn reply, HMRC said: "It takes 72 hours for an online return to be processed, you can go back in and amend after that time." Addressing the query about tax on their contributions, HMRC added: "Yes, you gross up by the 20 per cent basic rate that the pension scheme claim back."‌With private pensions, you are entitled to claim tax relief at source on your contributions — this includes SIPPs and certain workplace schemes. If you hold a SIPP, most providers will claim tax relief at the standard 20 per cent rate on your contributions and add the sum directly to your pension pot.The taxpayer also asked for clarification on the terminology being used here. They questioned: "Once it's been through that 72 hours, does processed mean checked or is that separate?"Article continues belowHMRC outlined how the system works: "That's the initial checks, returns can always be subject to further checks, but usually the 72 hours is sufficient." Those on the higher or additional rate for income tax must submit a claim to receive the extra tax relief, beyond the standard 20 per cent.'We can adjust'The taxpayer had a further query for HMRC. They noted that the sum they will stash away in their SIPP this year will likely be lower than the figure they paid in during 2025/2026. They asked HMRC to explain what happens given the two amounts would be different.HMRC confirmed it can make changes to a person's record in such cases. The tax authority said: "We can adjust for different amounts each year, so long as you fill the return out correctly."Choose Daily Mirror as a 'Preferred Source' on Google News for quick access to the news you value.‌HMRCPensionsTaxDepartment for Work and PensionsMoney Matters