Those grading from the UK but using a US grading service (like PSA, BGS or CGC) will generally find it easier to grade using a middleman as they can deal with the international shipping and the customs charges. UK-based companies likeTrustGradingandDan’s Pokestopare very reputable for this...
Before CGC comics, collectors were at the mercy of vendors to determine the grade and value of a comic book. In addition, there were no quality standards for comic book grading, which meant there was much discrepancy amongst collectors about the condition of various books....