Effective April 2015, the Marriage Allowance is calculated as 10% of the Personal Allowance. This is written into the Income Tax Act 2007...

For eligible taxpayers in 2017/18, the Allowance lets a taxpayer transfer £1,150 of their unused Personal Allowance to a spouse or civil partner, i.e. 10% of £11,500.

The UK Autumn Budget on 22 November 2017 announced the value of the Personal Allowance for 2018/19 as £11,850.  Therefore, it stands to reason that the Marriage Allowance for 2018/19 is £1,185.


The Income Tax Act 2007 (55B) says that where the resultant calculation is not divisible by 10 then it is to be rounded up.  The next value that is equally divisible by 10 is £1,190.  This explains why the OOTLAR (Overview of Taxation Legislation and Rates) has been sneakily updated with this figure on page 192 when the version published after the UK Autumn Statement read £1,185.

So, comparing the value to 2017/18:

Tax suffixes M and N are used where couples have decided to transfer (N) or receive (M) monies to their partner using the Marriage Allowance.  So, assuming that the full £1,190 is given or received in 2018/19, this leads us to the following uplifts, compared to 2017/18:

It’s a worry though

It was a colleague that alerted me to the fact that the OOTLAR had changed.  It was not HMRC, it was not any update E-mail from Gov.UK.  Which makes you wonder what the point of the update facility on Gov.UK is when the OOTLAR still says ‘published 22 November 2017’.  This is true – it was published as version 1 but we are now up to version 7!

I am making the profession aware of this so that the incorrect future is not quoted in factcards and software help text releases for the new tax year.

Join our newsletter