Low Serial Numbers, Variants and Error Notes

This category includes Bank of Portugal notes with special features sought after by collectors, such as low serial numbers, rare prefixes, unusual signature combinations, printing variants and production errors. These notes stand out from regular issues due to their scarcity, technical uniqueness and historical relevance. Highly valued items include notes with very low serial numbers, rare letter combinations, plate variations, colour shifts, misalignments, printing flaws and other anomalies resulting from the manufacturing process. These variants and errors make each piece unique and highly collectible, forming a specialised and increasingly appreciated segment within Portuguese paper‑money collecting.