Is DWP just a debt collector for Tax Credit debts? To which of them should questions./disputes go?

I am finding the subject of UC and TC debts increasingly puzzling. 

I am dealing with someone who has multiple deductions and sanctions.

UC have given me details of all of these, bar the HMRC debt - they can only tell me what they are deducting.

For any other information, they refer me to HMRC (involving more authorisation-getting, letters, etc)
UC seem to regard themselves as debt collectors for HMRC and that is all.

As far as I can see, the UC (Transitional Provisions) Regs do just refer to recovery but the D&A Regulations say (looking at Regs 42 and 43) that ‘where on consideration of a claim or other matter…an issue arises’ (or an appeal) that ‘falls to be decided by HMRC’ - ‘The SoS must refer that issue to HMRC’.

https://www.legislation.gov.uk/uksi/2013/381/regulation/42/made

What decides whether it is an HMRC matter is in S8 of the SSC Transfer of Functions Regs 1999. https://www.legislation.gov.uk/ukpga/1999/2/section/8

In short, does this mean that if DWP decide the matter is not one for them to decide, they should not make me trail off and seek information from HMRC, but that they are obliged to refer it to HMRC?

PS - Arrrrrrrrrrrg.

The legislation you refer to is concerned with various things related to NI contributions, statutory payments (e.g. SSP, SMP) and so forth. The duty to refer is in respect of matters connected with those things, such as whether NI payments have been made. It has nothing at all to do with tax credits.

Anything to do with decisions on tax credits remains with HMRC. The Universal Credit legislation made minimal changes to Tax Credits legislation - the majority of changes arise from a transition to UC making tax credits only payable for part of a tax year and triggering in-year finalisation of a tax credit award. As far as tax credit overpayments are concerned the UC system merely acts as a debt collector. See section 28 of the Tax Credits Act 2002 and in particular subsection 28(1)(b) - http://www.legislation.gov.uk/ukpga/2002/21/section/28.

Any queries/disputes/appeals regarding decisions on tax credits leading to an overpayment need to be taken up with HMRC.

Ah - wrong tree. Ta.

I’ll prepare the TC689 etc etc etc!