Have got a bit stuck on a question about tax credits claims. First: has anyone got, or can they direct me to, a copy of the TC600 guidance notes in force from April 2017 to April 2018? I can find 2018-19 but nothing from the year before.
Second: an EEA national makes an application for tax credits. There is a s.14 entitlement decision & subsequent appeal as he hadn’t provided information about his children when requested. He wins at FTT and is found to be entitled to WTC and CTC. At the permission stage, HMRC discover that there’s a social security coordination angle which allows them to argue no entitlement (&, although this is not spelled out, no valid claim), as he made a single claim which should have included his wife, who was residing in an EEA state. This scenario is not one which is covered by the relevant tax credits guidance notes: it is unclear in what capacity he has/had to claim (the only scenario which is clearly covered is that when children are abroad). The only viable arguments seem to come from reg.5(3) and possibly 13(3) at a stretch, but trying to avoid the difficult justiciability arguments raised by ZM/CI etc.
The situation is doubly difficult because he was supposed to have made a unitary claim for tax credits which could be determined two ways: as a single claim for WTC and as a joint claim for CTC (as WTC not covered by the Regulation). It’s unclear what mechanism allows HMRC to do this (and why this can’t e.g. operate in the other direction), but this seems to give rise to (non-justiciable) policy/public law arguments rather than ones which can run in the UT. The argument is that either (i) he made a joint claim; (ii) he made a single claim which could be treated as a joint claim; OR (iii) he made a defective joint claim which was sufficient in the circumstances to constitute an effective claim.
The most promising way through seems to be (i) via reg.5(3). The information about his wife was not information that was ‘required’ of him (citing e.g. MS v SSWP (JSA)  UKUT 206 (AAC) on reg 4 of the Claims and Payments Regs 1987 + looking at e.g. overpayment cases on Reg 32(1A)). It follows that the claim was not defective. However, I’m not sure where that leaves the claim? It might be procedurally effective, but it doesn’t feel like a particularly attractive argument to say that an incomplete claim form for tax credits which doesn’t include a spouse igives rise to an entitlement to a joint award of tax credits. Can anyone help me reason through this final step?