PAYE81600 | PAYE operation: international employments: leave pay for period of duty abroad
From HM Revenue & Customs · PAYE Manual
Arrivals in the UK
The Employment Income Manual (see EIM33061) will confirm if leave pay for a period of duty abroad may be liable to tax as earnings
If leave pay is liable to tax, tell the employer to include it in the pay against which the new code operates
If leave pay is not liable to tax, tell the employer to include it in the earnings to which code NT was applied