-ize is correct in British English as well; if anything it is more "original" as it comes from the Greek -izo (iota, zeta, omega), which is the origin of the su

-ize is correct in British English as well; if anything it is more "original" as it comes from the Greek -izo (iota, zeta, omega), which is the origin of the suffix. In fact Oxford English Dictionary (OED) spelling, and the Hart's Rules guide, are for organize, not for organise. (On the other hand, analyze is American while analyse is British.)