Thank you for your comments. I am a US citizen and deciding whether to take out the whole pension in one shot ( i understand higher tax bracket etc).
Unless your pension sums are very small taking them out all at once is not tax efficient.
You are a ware of the "tax bracket" issue, but you will also loose all that tax deferred growth.
Just to be clear, are you saying the US won't want a 10% penalty if I take the distribution from the UK pension like they would if i took early distribution from a us 401k or IRA before age 59 1/2?
Yes, the UK pensions are governed by UK law. All the US wants is for you to include the income from those pensions on your 1040.
Also is this income from the US perspective passive or general as have plenty of general/income tax credits but very little passive.
You can use the general basket, but there will be no UK tax due on your UK pension if you take the money out if your are US resident.
Regarding basis, i have tax returns showing that any employer contributions were treated as income on my U S tax return- am I missing something or is this enough?
If you've paid tax on contributions already you will have to work out your tax free basis and enter the appropriate amounts on your 1040 line 16a and 16b
And just to be clear, if I leave the pension here and return to the states there is no time limit that I have to leave the pension in the UK in order to avoid UK taxes and from the flip side if i take a full lump sum in say January in the UK and return to the states in say Feb then I merely do a UK return like normal accounting for the distribution and there is no problem with the US even though i returned to the US say 1 month after distribution ? Sorry to be so long winded.
How, and to who, you pay the tax will depend on your tax residency. If you leave the UK you should file a P85 to establish that you are leaving the UK and returning to the US. If you are leaving the UK permanently and establish non-UK residency, there should be no UK tax on the pension withdrawals.
The timing of your UK pension income means nothing to the IRS as you are always taxed by the US on your worldwide income.