I've had quite a run-around these last few days from the HMRC on this issue.
Firstly, there was the call from the HMRC "Foreign Pensions Specialist" (he called Sat morning, after I had tried the helpline and been advised their specialist would call me within 4 weeks), who said I should have completely ignored the Foreign Earnings section of my Self-Assessment form and should have entered nothing there. He advised me simply to write claiming a refund of UK tax paid on these payments.
This I did.
A few days later I received a form "DT-Individual", which was entitled: "Application for relief at source from UK income tax and claim to repayment of UK income tax".
Needless to say this was HMRC's pathetic misreading of my letter (it was very clear and very correct), it was the wrong document, was completely inappropriate and completely useless.
Yesterday I then contacted an organization called: Tax Help for Older People (
http://www.taxvol.org.uk/) who seem quite switched-on and have certainly been helpful - so far.
They claim to have the use of a direct Hotline to specialists at the HMRC and, having explained my problem, I was put through to an HMRC tax specialist who was polite, seemed intelligent and understanding. She went away and checked my file etc, came back and apologized that her colleagues had obviously misunderstood my letter.
She has undertaken to look into my claim and get back to me.
I've also requested HMRC pay the interest demanded by Neubrandenburg (about €610) as well as the 6,000pds UK tax wrongly paid.
One thing I would say is that dealing with the German Tax Authorities, whether Neubrandenbrug or local Finanzamt level, is much more straightforward and "humananized" than dealing with HMRC. Getting competent advice, explained in a polite and straightforward manner is the Norm in Germany.
I'm pretty disgusted at the obvious deficiencies I've experienced so far in HMRC's public dealings.
If taxvol.org.uk do manage to help me on this I'll make a donation - they are a charity staffed by volunteers.