If you are asking how to know if that certain mobile number prefixes belongs to what network, we will share you the list of numbers to what network it belongs. Nowadays our mobile operators offer affordable promos like unlimited call and text, text to all networks and all net calls unlike before where call and texts rates is too costly. That time we are very careful of texting to unknown mobile numbers that does not reflect on our phonebook. Same goes with unlimited texts and calls promo where you need know the network of the number you are trying to call or text to avoid extra charges.
In Philippines, we have more than 3 mobile network provider namely Smart, Talk N Text (TNT), Globe, Touch Mobile (TM), Red Mobile and Sun Cellular. We only list common sim numbers out of of above mentioned network provider as we are not familiar with other networks, but if you have the idea about other provider you can feel free to drop a comments for us to update.
Philippines mobile network number series
Prefixes / Starting numbers:
Smart Communications / TNT
Talk N Text or TNT (cellular service of Smart)
Globe Telecom / TM
Touch Mobile or TM (subsidiary of Globe)
Red Mobile (subsidiary of Smart)
List is not yet complete; feel free to add other details by hitting us a comment.