What Is a CP575, and Why You Need It for Text-Message Registration
Before your business can send text messages (SMS) to customers in the United States, US carriers require your business to be registered — a process called A2P 10DLC. That registration has to match your business to official IRS records exactly, and the document that proves the match is your CP 575. This article explains what the CP575 is, why it's needed, and what to send us.
Why registration is required at all
US mobile carriers now require every business that sends automated or bulk texts to register its identity first (this is the "A2P 10DLC" system, run through an industry body called The Campaign Registry). Registration is what lets your appointment reminders, follow-ups, and campaigns actually deliver instead of being silently blocked as spam.
Symphony Core submits and manages this registration for you — but a few pieces of information have to come from you, and they have to be exactly right.
What a CP 575 is
The CP 575 is the confirmation letter the IRS mailed to you when it issued your EIN (Employer Identification Number). It states, in the IRS's own records:
- Your exact legal business name (including
LLC,Inc., punctuation, and spacing) - Your EIN
That exact legal name + EIN pairing is the "source of truth" carriers check your registration against.
Why it matters so much
The single most common cause of registration failure or delay is a mismatch — the legal name or EIN entered during registration doesn't exactly match IRS records. Even a small difference (a missing "LLC", a comma, an abbreviation) can get the whole registration rejected.
The CP575 removes the guesswork: it gives us the precise spelling and formatting the IRS has on file, so we register it correctly the first time.
Important: Don't rely on names from a W-2 or W-9 — those can differ from official IRS records. The CP575 is the one that carriers validate against.
What if you use a DBA / brand name?
Many businesses trade under a brand or DBA ("doing business as") name that's different from their legal entity name (for example, legal MCG Real Estate LLC, brand CT Building Broker). That's completely fine:
- We register your legal name + EIN (from the CP575), and
- We note your DBA in the registration so your brand name is recognized.
- Make sure your website reflects your DBA/brand name — carriers do an automated check that your site matches the brand you're texting under.
What to send Symphony Core
To get your registration moving, please provide:
- A copy of your CP 575 (a clear PDF, scan, or phone photo is fine)
- Your exact legal business name and EIN (we'll confirm against the CP575)
- Your DBA / brand name, if you use one
- Your business website (it should show your brand/DBA and a privacy policy + SMS opt-in language — we help with this)
Lost your CP 575?
The IRS only issues the CP575 once and won't send a duplicate — but you can request an equivalent letter that carriers accept just as well:
- Call the IRS Business & Specialty Tax Line at 1-800-829-4933 (weekday business hours)
- Ask for a Letter 147C (EIN verification letter)
- They can mail or fax it to you; send us that instead of the CP575
What Symphony Core handles
Once you've sent the items above, we take it from there — submitting your brand and campaign registration, writing the compliant sample messages and opt-in language, and following up on any carrier questions. Registration review typically takes a few business days; occasionally longer the first time a brand is vetted.
Key takeaways
- Sending business SMS in the US requires A2P 10DLC registration; we handle the submission.
- Your registration must match your exact IRS legal name + EIN — the CP 575 proves them.
- Mismatches are the top cause of rejection, so the CP575's exact spelling matters.
- A DBA/brand is fine — we register the legal name and note the brand; your website should show the brand.
- Lost the CP575? Request a 147C letter from the IRS instead.
Questions? See How to Get Support.