The SY postcode area, also known as the Shrewsbury postcode area, is a group of 25 postcode districts in England and Wales, within 32 post towns. These cover most of Shropshire (including Shrewsbury, Oswestry, Ludlow, Bucknell, Whitchurch, Bishop's Castle, Craven Arms, Church Stretton, Ellesmere, Lydbury North and Llanymynech), north Powys (including Montgomery, Newtown, Welshpool, Caersws, Llanbrynmair, Llanfechain, Llanfyllin, Llandinam, Llanidloes, Llansantffraid, Machynlleth and Meifod), and north Ceredigion (including Aberystwyth, Borth, Bow Street, Tregaron, Talybont, Ystrad Meurig, Llanrhystud and Llanon), plus small parts of south Cheshire (including Malpas) and north Herefordshire, and very small parts of Gwynedd and Wrexham County Borough.