By enrolling in Marriage Allowance, eligible married couples or individuals in a civil partnership may be able to lower their annual tax by up to £252.
Married couples are urged to take advantage of a benefit that could lower their tax liability.
Couples or individuals in civil partnerships can split their personal tax allowance and receive savings on up to four years' worth of taxes by using the marital allowance.
If one partner earns less than the personal allowance threshold of £12,570 and the other pays income tax at the basic rate, which is often on an income between £12,571 and £50,270, a couple may qualify.
Couples who qualify may transfer 10% of their tax-free allowance to their partner, lowering their annual tax liability by up to £252.
Even long-married couples can submit an application, and benefits can be backdated by four years to encompass any tax year beginning in April 2018.
We want to make sure that people are receiving crucial financial support at a time when they most need it, said Angela MacDonald, deputy chief executive and second permanent secretary at HM Revenue & Customs.
Those who are married or in a civil partnership may be eligible for tax breaks worth up to £1,242, which would put more money in their wallets.
Couples can check their eligibility and learn how to apply here.
Couples who cohabit but are not married are not eligible for the allowance.
The allowance is presently used by more than two million couples in the UK.
If you or your partner's employment situation has changed, HMRC advised you to double-check your eligibility.
The surviving partner can still make a claim if their spouse passed away after 2018, according to HMRC, by calling the income tax hotline.
According to research done in 2017 by the insurance company Royal London, married persons in the UK who haven't claimed the allowance may be out £1.3 billion in total.