Can I use "The Thompson Family" on the envelope?

You can, but formal etiquette advises against it. "The Thompson Family" is vague and leaves guests guessing about who exactly is invited.

• Casual weddings: a family name on the envelope is generally acceptable.
• Formal events: list each invited guest by name instead.
• Why it matters: naming people individually removes any doubt about whether kids, in-laws, or adult children are included.

When in doubt, spelling out names is the safest way to set clear expectations for your guest count.