You need your legal entity name, EIN exactly as printed on your IRS letter, business address, and a live website. Carriers cross-check the EIN and address character-for-character — a mismatch is the #1 rejection.
In your Solto account: Settings → Phone Numbers. Pick a local area code your clients recognize (Dallas metro: 214, 469, 972, 945). About $4/mo.
Settings → Phone System → Trust Center. This is carrier registration HQ — click Start Registration under A2P Messaging (SMS).
The wizard pre-fills from your Business Profile, so fill THAT out first (legal name, EIN, address, business email). Watch the traps: each step only saves when you hit Continue; the industry list needs scrolling; the region checkbox is a styled label.
Your site must show your real business info, plus a privacy policy stating mobile info is never shared for marketing, and terms with STOP/HELP and message-rate language. A 'coming soon' page = automatic rejection.
Low Volume conversational fits most agents. Describe how people opt in, paste sample messages including an opt-out line. Fees: ~$24.50 one-time (incl. fast-track) + up to $11.03/mo carrier passthrough — charged when you submit.
Fast-track review runs ~3 business days. Check the Trust Center daily; rejections almost always cite the website — fix and resubmit the same day.
Once approved: text yourself, then reply STOP (confirm it suppresses) and HELP (confirm the auto-reply). Now you're carrier-legal.