The listed price for ChatGPT Plus is $20 per month, but the actual charge can...

https://www.runway-bookmarks.win/chatgpt-plus-lists-at-20-per-month-but-the-actual-price-you-pay-can-range

The listed price for ChatGPT Plus is $20 per month, but the actual charge can vary between $13 and $27 depending on where you subscribe. This happens because of extra fees like VAT or GST in some countries, or app store markups on iOS and Android