A client just cancelled their Thursday 4pm. Three people on your waitlist would take it in a heartbeat.
SlotFill texts your waitlist the moment a therapy session opens. First to respond gets it. You never pick up the phone.
The Cost of Empty Slots
You already know this feeling
It's 9am and you see it — a cancellation for this afternoon. Your 3pm just texted that they can't make it. That's $150-200 gone, and your afternoon now has a hole in it.
You could call the three people on your waitlist. But you're about to start a session, and by the time you're done, the slot is in two hours. Your office manager (if you have one) is juggling intake forms and insurance calls.
So the slot sits empty. Again.
What if your waitlist worked for you?
When a session opens, tap once. SlotFill texts every client who's asked to be notified. The first one to reply "YES" is booked.
No phone tag with three families. No back-and-forth texts. No "let me check my schedule and get back to you." Just: slot opens, text goes out, slot fills.
Built for how therapy practices actually work
Weekly recurring clients cancel all the time. Life happens — sick kids, work conflicts, forgot to tell you last session. SlotFill doesn't spam your whole caseload. You choose who gets notified for each opening.
If you're a therapist with a full caseload, you probably have 5-15 people waiting to get in. Those people would love to grab a one-off session while they wait for a regular slot. SlotFill makes that possible without you managing it manually.
No app for clients to download. It's a text message. Your clients reply YES or ignore it. That's the whole interaction on their end.
HIPAA-conscious. No appointment details in the text. No client names exposed. Just "a session is available at [time] — reply YES to claim it."
Everything you need to fill last-minute openings
Simple, fast, and designed specifically for therapists
Instant Broadcast
Send SMS to your entire waitlist in seconds when a slot opens up
Never lose revenue to last-minute cancellations
First-Claim Wins
Fair system where the quickest responder gets the appointment
Fair and transparent for your clients
Simple for Clients
One-tap claim link. No apps to download, no accounts to create
Higher response rates with zero friction
How It Works
Three simple steps to fill your cancelled appointments
Client Cancels
Create an opening in 30 seconds
Broadcast
SMS sent to your waitlist instantly
Slot Filled
First to tap claims it
Built with Privacy in Mind
Your client data stays secure. Period.
Encrypted Data
All data encrypted in transit (TLS 1.3) and at rest (AES-256)
HIPAA-Conscious
We store only scheduling data, never clinical notes or PHI
US-Based Servers
Data hosted on SOC 2 certified US infrastructure (Supabase, Vercel)
Data Ownership
Export or delete your data anytime. Your client list is yours
Sound Familiar?
These are the problems SlotFill solves
"I spend 30 minutes calling down my waitlist"
Manual phone tag is exhausting. By the time you reach someone, the slot is gone.
"Clients want to come this week, not next month"
Your waitlist clients are motivated. They just need to know when something opens.
"Every empty slot costs me $150-200"
Last-minute cancellations aren't just inconvenient—they're expensive.
One empty therapy hour costs you $150-200. SlotFill costs $39/month. Fill one extra session a month and you've paid for a year.
Start free, upgrade when you need more
Free Trial
Try everything with no commitment
- 50 SMS included (~5 cancellations)
- Unlimited waitlists
- Unlimited clients
- First-claim system
- Full access to all features
Pro
Everything you need to fill cancellations
- 300 SMS per month (~30 cancellations)
- Unlimited waitlists
- Unlimited clients
- Analytics dashboard
- Email support
- Buy extra SMS anytime
Frequently Asked Questions
Everything you need to know about SlotFill
When you broadcast an opening, all eligible clients on your waitlist receive an SMS with a unique claim link. The first person to tap the link and confirm claims the slot. Everyone else sees a 'slot already claimed' message. It's fair, fast, and transparent.
No! That's one of the best parts. Clients receive a simple SMS with a link. They tap it, see the appointment details, and tap again to confirm. It works in any mobile browser - no app downloads, no account creation, no passwords to remember.
Absolutely. We use industry-standard encryption for all data in transit and at rest. We don't store session notes or clinical information, only the minimum contact info needed for scheduling. Your client list stays yours.
You have two options: add clients manually through your dashboard, or share your unique waitlist join link. Clients can add themselves via that link - they just enter their name and phone number. You can review and manage all waitlist members anytime.
Your waitlist is sitting in a spreadsheet. Your cancellations are sitting in empty hours. Connect the two.
Start your free 30-day trial.
No credit card required · 50 SMS included · Cancel anytime