I would urge all those Serving to consider carrying out a self-assessment - it's easy, doesn't cost anything and allows you to claim for charitable giving, professional memberships etc. Clearly, if you have second income (eg partner's part-time work, rental income/holiday letting), self-assessment is essential, and generally beneficial.
Although in the above case it appears that the correct PAYE was deducted, DO NOT rely on JPAC to have made the correct deduction. They are not tax-experts and nor are we.