The problem of missing demands for payments on account (PoA) first arose in 2017/18, but the issue appears to be far more widespread for 2018/19.
There is a computer glitch with the processing of some 2017/18 SA tax returns, such that requests for PoAs for 2018/19 have not been raised. HMRC has drawn attention to the problem in its Agent Update issues 71 and 72, but has indicated it won’t be solved before 31 July when the second PoA for 2018/19 is due for payment.
There are several issues arising from this computer error.
If your client did not receive a demand for 2018/19 PoA in January 2019, they may have paid only the balancing payment due for 2017/18 by 31 January 2019, and not the higher figure including the 2018/19 PoA which you will have advised.
If the taxpayer did make the correct PoA for 2018/19 as advised in January, although there was no PoA demanded, this payment will be treated as a voluntary tax payment. You can ask HMRC to add the PoA due to the taxpayer’s record, to ensure the voluntary tax payment is not repaid. This adjustment can’t be done if the taxpayer has not in fact made a voluntary payment on account.
If the taxpayer’s tax account was corrected to reinstate the PoA for 2018/19, a demand for the second PoA for 2018/19 should be issued in July.
If the taxpayer’s account is still not showing a PoA due for 2018/19, and the taxpayer has not made a voluntary payment, it may now be too late to create a PoA for the second payment due on 31 July.
HMRC has confirmed that if the demands for PoA have been omitted from the taxpayer’s statement, the taxpayer will not be charged interest as long as all of their 2018/19 SA tax due is paid by 31 January 2020.
There is a risk that any voluntary payments of PoA will be automatically repaid by HMRC. It may be easier to deposit the tax due into a savings account and pay it all in January 2020.