Cashed in pension, claiming back tax deducted.

Hi, I'm helping out a friend. He's British, living in the Czech Republic and has cashed in his UK pension, i.e. took a pension commencement excess lump sum. He got 25% of the pension tax free and then on the balance (c.£46k) around 30% of this was withheld by the pension provider and forwarded to HMRC. He wants to claim a lot of this tax back. I'm reading online that a lot of people claim the whole amount of tax back, based on the double treaty agreement, then would declare the income to the Czech tax people. It sounds like he would need to go and get some form stamped by the Czech authorities beforehand which might be a pain. Anyway, all things considered my friend would prefer it if it was possible to pay the income tax in the UK. So claim his personal allowance and pay 20% income tax on the rest. This would be simpler for him and I suppose better for HMRC. Is it possible to pick which route he goes down or is he forced to take a whole refund and declare the income in Czech Republic? If it's possible to just claim the partial tax refund in the UK, is there a one size fits all form to do this, as opposed to having to set up a Government Gateway account, register for Self Assessment online, etc? 

Hi,
We are unable to comment on individualised scenarios in this forum, for specific advise on their personal circumstances your friend would need to contact our Self Assessment team.
Self Assessment: general enquiries
Alternatively, they may wish to engage the services of a professional advisor/accountant to assist with their enquiry.
Thank you.

Really? Why can't you just view it slightly differently and view the query in generic terms, about how a pension commencement excess lump sum is taxed? Does the tax on that lump sum need to be reclaimed in the UK or the country of residence?

Hi,
Much depends on the tax treaty between the UK and the other country.  
You can find all of the UK tax treaties at Tax treaties.
Thank you.