Thanks to all for your replies. In my case the overpayment is greater than the monthly tax deduction so can I expect to receive the whole rebate next month or in instalments? To pay me the whole rebate next month would require a negative tax deduction. Is that possible? I have asked the pension provider for a clarification but they have not responded.

In August my pension provider's fund was sold to an insurance company. On August 25th I received a revised notice of coding with a large reduction in my code. In October my pension statement showed a 50% reduction in my net pension. I notified HMRC who admitted an error and issued a new notice with my old code restored. I now realise that they had deducted all of my net pension income for the first 5 months of 2016/7 (tax already deducted) from my tax free allowances which caused my code to fall dramatically. I am now owed the overpaid tax but I do not know who is supposed to repay it, HMRC or my new provider. It is unacceptable that it is just deducted from tax due each month as that would take 4 months for the deficit to be cleared. I need a lump sum payment.

HMRC made an error in my 2016/7 tax code which resulted in a large overpayment of tax on my pension in October 2016. HMRC have admitted their mistake and issued a new, correct, code. Who is responsible for repaying me? My pension provider or HMRC?