DT applications and claims - Types of income: Pensions and Annuities
Widows of Armed Forces personnel
Pensions (or “retired pay”) paid to widows of Army. Navy and Air Force officers do not have tax deducted from them but are reported for assessment. Generally, pensions paid to widows of other ranks are not reported and are not assessed.
You may have a case where someone has other sources of UK income and the Inspector of Taxes dealing with that person requires an authority from you specifically exempting the pension from UK income tax. You should consider the claim under the terms of the Double Taxation Agreement in the normal way.