How to Write Telegram Phone Number Format: E.164 International Format, Leading Zero Handling, and Multi-Country List Organization Order

Telegram identifies numbers in E.164 international format: country code plus the number with domestic prefixes removed, digits only. This article provides the order for organizing multi-country contact lists, including separators, 00/011 prefixes, leading zeros, Excel digit loss, deduplication, and grouping by country, and lists numbers that still need separate handling even after correct formatting.