Prismm/AllSeated Is Shutting Down: What to Do Now

If you planned a wedding, corporate gala, or other event on AllSeated in the last decade, you probably have muscle memory for its floor-plan tool. That tool doesn't exist under that name anymore, and soon it won't exist at all. AllSeated rebranded to Prismm, Cvent bought it, and Cvent is shutting the standalone platform down. Here's what's actually happening and what to do about it before the lights go out.

What we know about the shutdown

Cvent acquired Prismm (formerly AllSeated) in 2025 and is retiring the standalone platform, folding customers into Cvent Event Diagramming (the former Social Tables). The dates have moved once already. Cvent first gave October 1, 2026 as the view-only date and December 31, 2026 as the close; in September 2026 it extended the runway. As Cvent's own page puts it today:

• Since August 26, 2026: new events can only be created in Cvent Event Diagramming, not in Prismm.
• Until June 2027: you can keep managing the Prismm events you already have.
• After June 2027: Prismm access ends, and your Prismm work stays viewable, read-only, inside Cvent.

So nobody loses an event this week. What changed on August 26 is that your next event can't start in Prismm, which is when most planners pick a replacement.

Two details matter most: templates, favorites, and saved object groups don't carry over automatically to Cvent's replacement, and Prismm's floor-plan files don't import into most competing tools. Guest lists export cleanly as CSV; seating layouts don't — moving those means rebuilding, not transferring.

Sources: Cvent's Event Diagramming resources page, checked September 29, 2026. PlanSeats and Floors.live now give June 2027 too. Cvent's older migration FAQ and some guides still say October 1 and December 31; the resources page is the newer one. If the date matters for a contract, check Cvent's page on the day.

Step-by-step: export your data

Do it while you still remember why each table is set the way it is, not in May 2027. After June 2027 you can look at your old work in Cvent, but you can't edit it there.

1. Export your guest list as CSV. In Prismm, open Reports, set the Report Type to Guests, configure the Fields you want (name, party size, RSVP status, meal choice, table assignment), click Generate, then Export to CSV. Do this for every active event — it doesn't carry over between events automatically.
2. Export your floor plan as PDF or image. You won't be able to re-import this into most other tools, but you'll want the visual reference while you rebuild — table numbers, room layout, and where doors, dance floor, and head table sit relative to guest tables.
3. Write down table shapes and seat counts separately. A CSV won't tell you that Table 4 is a 72-inch round seating 10 or that Table 9 is a king's table seating 20. Make a simple list: table number, shape, capacity. You'll re-enter this manually in whatever tool you move to.
4. Pull your seating rules out of your head (or old notes), not just the software. Prismm doesn't export "keep together / keep apart" logic in a reusable format. Before you forget which constraints mattered, write them down as pairs: who must sit together, who cannot share a table, and any VIP or head-table rules (wedding party, sponsors, officiants, honorees).
5. Save any client-facing exports you've already sent — floor plans, escort card lists, place card data — as your fallback if the rebuild takes longer than expected.
6. Pick a replacement and re-enter tables, seat counts, and rules first, guests second. Getting the room right before you assign a single guest saves you from redoing the layout twice. If your guest report included the table column, some tools (Seatwise is one) read it and put each guest back at their table on import.

What actually matters to carry over

Not everything from a Prismm event is worth rebuilding. Prioritize, in order:

1. Table shapes and seat counts — this is the skeleton of the whole chart and the hardest thing to reconstruct from memory later.
2. Keep-together / keep-apart rules — divorced parents, feuding coworkers, the two guests who requested to sit together. These are almost never written down anywhere but the old software.
3. VIP and head-table assignments — sponsors, honorees, wedding party, executives. Get these locked before you auto-seat everyone else.
4. Guest list with RSVP and meal data — this is the one thing that exports cleanly as CSV, so it's the least urgent to protect manually.

Honest comparison of replacements

None of these are a perfect drop-in for Prismm's full event-design suite (3D rendering, AV diagramming, room measurement). If all you need is guest and table seating — which is most weddings, galas, and dinners — here's how the realistic options compare:

PlanSeats is marketing itself hardest as the direct Prismm replacement and has migration content built for exactly this moment, which is worth a look if you want something closest in spirit to Prismm's client-collaboration features. SeatPlan.io and PerfectTablePlan are the longer-standing options — PerfectTablePlan if you want a one-time desktop purchase and don't mind installing software per machine, SeatPlan.io if you want cloud access without a recurring fee for a single event.

If you're planning one event and don't want a subscription at all, that's where Seatwise fits: it's free to lay out tables, paste your guest list (the Prismm guest CSV works, table column included), set keep-together/keep-apart rules, and auto-seat, with a single $12 payment to export the floor plan, per-table lists, a printable "Find your seat" board, and an escort-card CSV. Nothing uploads to a server, so there's no re-run of the "where does our data live" conversation you may already be having about Prismm.

For corporate planners and venues running many events

If you're a planner or venue with a dozen-plus events a year on Prismm, the calculus differs from a single couple migrating one wedding — see our table math guide if you're rebuilding layouts from scratch and want a starting point for table counts.

1. Volume math changes the pricing comparison. A per-event flat fee (SeatPlan.io's $8, Seatwise's $12) is cheap for one event and adds up across dozens; a monthly or annual plan (PlanSeats Pro at $39.99/mo, SeatPlan.io's Event Manager at £35–40/mo, or Seatwise's Planner licence at $49 a year for unlimited events with your name and logo on every export) usually wins once you're running more than three or four events a month.
2. Reusable venue templates matter more to you than to a couple. If you run events at the same venue repeatedly, prioritize a tool that lets you save a room layout once and reuse it — check this explicitly before committing, since Prismm's own templates don't migrate automatically to anything, including Cvent's own replacement.
3. Export formats decide who gets paid on time. Confirm any shortlisted tool exports per-table guest lists in a format your catering and AV vendors already accept (CSV, PDF) — don't assume parity with what Prismm produced.
4. Start the migration with your highest-volume upcoming events, not chronologically. Rebuild the layouts for your next three events first, in whatever tool you pick, rather than trying to migrate your entire historical event library — most of that is archival and doesn't need to survive the cutover.
5. Trial two or three tools on your next new event, since that event has to start outside Prismm anyway, with your exported CSVs in hand for a side-by-side test rather than under deadline pressure in spring 2027.

The deadline that actually matters

For new work, it has already passed: since August 26, 2026, a new event can't start in Prismm. For old work, June 2027 is the last day you can edit. Export your guest CSVs, table lists, and seating rules now, while each event is fresh in your head, and June 2027 becomes a formality instead of a scramble.