1.3 to 1.6 i think no problem....but 1.3 to 1.8 is all along cannot, just depends on how strict they were only......coz last time they really close one eye (wif money lah of coz) n approve em....now strict liao.....if u wanna convert from ur 1.3 to 1.6 mivec (4G92) shouldnt b a problem as long as ur conversation is complete n meets some of their requirements....