Can I text my customers?
Yes, when they agreed to receive texts from you. The agreement is the part that matters. Having their number is not the same thing.
This is a product note, not legal advice.
A customer agrees when they opt in on purpose: a checkbox at checkout that mentions texts, a form that says who will text them and why, a keyword they send because a sign told them what they would get. The language should be plain. They are signing up for messages, from this business, and message and data rates may apply.
They have not agreed just because they bought something, booked a table, or left a number for a delivery driver. If you want to text that person later with an offer, ask then, while they are still standing there or still on the page.
What to send once they have
One reason, the business name, and a way to stop. Reply STOP is enough to say, and then it has to work. Writing the text is the rest. The legal note covers the US consent rule in slightly more detail.
Keep a record of how each number got on the list. You will be asked for it during 10DLC registration, and you will want it if someone complains.
If the honest answer to “how did we get this number?” is “we bought it” or “we are not sure,” leave it off the file.