Capture explicit opt-in at booking. Pre-checked boxes do not count under GDPR.

Record when and where consent came from, with a timestamp and the source: booking form, check-in, OTA redirect.

Give every message a way out. "Reply STOP to unsubscribe" on SMS, and honour WhatsApp unsubscribes immediately.

Set a retention period in line with local law. Three years is typical in the EU.

Ask which channel the guest wants. Do not assume. Defaulting to SMS and offering WhatsApp as an upgrade works well.

Stay within 160 characters on the GSM-7 character set. If you have to go longer, write deliberately for 306 characters, which is two parts.

Use a branded sender ID, for example "GrandHotel". Check whether the countries you send to support alphanumeric senders before you switch it on.

Avoid unknown URL shorteners. Use a branded short domain or the full URL. Shortened links from unfamiliar domains get filtered.

One call to action per message. Never stack a review request, an offer, and a survey into one send.

No all-caps and no rows of exclamation marks. Both trigger spam filters.

No emoji in SMS. They switch the message to Unicode encoding, which cuts the limit from 160 characters to 70 per part and can split the message oddly on some handsets.

Submit templates for Meta approval early, at least 48 to 72 hours before launch, and preferably sooner.

Keep template variables to three or fewer. Approval rates drop sharply above that.

Monitor the inbox so you catch the 24-hour free-form reply window after a guest gets in touch.

Use the WhatsApp Business API. Personal WhatsApp and the free Business app breach Meta's terms at any real volume.

Frame promotional content as a service notification. Purely promotional messages outside the 24-hour window are not allowed by Meta.

Attach media only when it earns its place. Unsolicited images and PDFs read as intrusive.

Schedule in the property's local time zone, not your server's.

Keep a blackout window, for example 9pm to 8am, with no outbound messages unless the guest started the conversation.

Cap it at about five messages per stay: booking confirmation, pre-arrival, post check-in, pre-checkout, post-checkout.

Delay post-checkout messages by two to four hours. Guests are travelling, and a message that arrives too early gets ignored or resented.

Do not chase. If a guest has not replied, leave that touchpoint alone.

First name only. A full name in a greeting reads like phishing.

One tone throughout. Formal or casual, but the same at every stage of the stay. Mixed tone undermines trust.

Only use data the guest knowingly gave you. Referencing a dietary note from a form they filled in months ago feels like surveillance rather than service.

At most one functional emoji per message, used to help scanning. Three or more reads as marketing.

Short sentences, active voice. On these channels every word is visible.

Send from a monitored inbox. A no-reply number removes the only real advantage these channels have.

Set response times by stage. In-stay complaints within 15 minutes, pre-arrival questions within 2 hours, post-checkout within 24.

Automate acknowledgement, never resolution. "Thanks, we are looking into it" is fine. Confirming something is fixed when nobody has touched it is not.

Have an escalation path so a serious complaint reaches the front desk or duty manager straight away.

Alphanumeric sender IDs are not supported everywhere. The US and parts of Asia-Pacific do not allow them. Check by market before activating, and ask us if you are unsure.

Template approval is Meta's, not ours. Allow 48 to 72 hours minimum. A campaign launched without an approved template simply fails to send.

Emoji shorten SMS. Unicode encoding drops the limit from 160 characters to 70 per part.

A missed WhatsApp reply closes the window. Once the 24 hours lapse you are back to approved templates only, and this is the most common operational failure on the channel.

Opt-outs are only as good as your syncing. If your PMS, CRM, and messaging platform do not share suppression lists in real time, an opted-out guest can still be messaged.