Can I send the invitation by email and WhatsApp at the same time?
To different guests, yes โ that is the guest-by-guest idea. To the same guest, no: pick the channel they actually read. Two arrivals of one invitation invite two replies, and reconciling them is exactly the busywork the page was meant to end.
What is the earliest I can send party invitations?
Long enough before that people can honestly say yes, which for anything casual means roughly three weeks. A date sent four months out gets answered optimistically and forgotten twice. Put the reply deadline on the page and send when the plan is real.
Do guests need an account or an app to reply?
There is no app to install โ the link opens in whatever browser they already have, and the RSVP button takes a name and an answer. No sign-up wall between a yes in the chat and a yes on the list.
How do I handle plus-ones across different channels?
Set the rule once on the page: plus-ones only inside the limits you choose. Then a guest arriving through email, chat or a forwarded link meets the same boundary, and you never have to be the one saying no in a conversation.
Someone answered in the chat and never touched the link โ are they in?
Not properly. The chat yes is a warm signal, but it is not on the list, and chats forget. Reply to them there, thank them, and ask once for a tap on the page. The deadline reminder will reach them too, since on the list they are not.