100 Pounds Ulster Bank

Ulster Bank Limited has issued high-denomination notes through De La Rue for decades, but the £100 remained a genuinely rare circulation item in Northern Ireland — most were used for interbank settlement and bulk cash handling rather than retail transactions, and many returned to the issuing bank without significant time in public hands.

Ulster Bank's right to issue its own sterling notes in Northern Ireland derives from legislation predating partition, a quirk that has never been revoked. The watermark security on this series was considered adequate for the period, though De La Rue would introduce substantially more complex features on successor issues through the 1990s.