Yahoo's SMS verification reject rate isn't really about the SMS provider — it's about the IP+fingerprint+number combo. Even premium SMS services hand you numbers that got burned through other Yahoo signups in the last 48h. Two adjustments before swapping providers: rotate to a clean residential IP per signup attempt (not just per session), and verify the carrier of the number matches the country your IP geolocates to. If you're hitting Yahoo from a US IP with a Filipino SMS number, it gets flagged before you even submit the form. If you've ruled that out, providers that historically held up better on Yahoo specifically are the country-specific ones (real US-carrier providers) rather than the cheap aggregators — but they're 2-5x more expensive per number.