Text-first contract signing with auto-resend
Sends signing requests by SMS link with no app download and nudges the client until they sign, for small businesses whose emails go to junk.
The problem
Reviewers of big e-sign tools say their clients' signing emails land in junk or spam, and some clients never check it. Others say clients have to download an app to sign and ask if there's any way to avoid that. One owner ends up with half the paperwork on paper and half electronic because clients struggle with the app, and another wants a plain resend button.
Who has it: Home-service companies, landlords, tutors, trainers and local event vendors whose customers are non-technical and live on text messages.
Who pays
The small business owner, who loses time and jobs when contracts sit unsigned in a spam folder. · $19/month plus SMS pass-through (about $0.02 per text)
Subscription with a monthly cap of SMS requests, and extra packs sold on top. Reach first users through niche trade communities such as landlord, cleaner and DJ groups.
What to build first
- Upload a document or pick a template and enter the client's mobile number
- SMS with a short link that opens a mobile web signing page, with no app and no login
- Auto-resend by text at 1 and 3 days, with a manual resend button
- Fallback to email if the SMS fails
- Audit trail with sent, opened and signed timestamps
- Searchable list by client, date and status
Suggested stack
Next.js Supabase Twilio Stripe pdf-lib
Starter prompt
Paste it into Cursor, Claude Code, Lovable or Bolt and iterate from there.
Build a mobile-first web app called TextSign. A business owner logs in, uploads a PDF or picks one of three built-in templates (service agreement, rental addendum, liability waiver), and enters a client name and mobile number. The app texts the client a short link through Twilio. The link opens a signing page with no login: the client reads the document, draws a signature on a canvas, and taps Sign. Use pdf-lib to stamp the signature, a timestamp and the IP onto the PDF, then store it in Supabase Storage and email copies to both parties. Track statuses (Sent, Opened, Signed) in a dashboard with a searchable list by client, date and status. Add auto-resend texts after 24 and 72 hours if unsigned, plus a manual Resend button, with email as a fallback. Add Stripe subscription billing.What could go wrong
Incumbents could add SMS delivery easily, and US SMS rules (10DLC registration) add setup friction. E-signature legal validity varies by country, so the tool needs clear terms and shouldn't promise legal advice.
Where we found it
- SignNow review: clients must download an app — A user says clients have to download an app to sign, and asks if there is any way to sign without one.
- SignNow review: junk mail and resend — Reviewers say some clients don't check junk mail and that the tool needs a resend button, since they sometimes send twice.
- SignNow review: half paper, half electronic — A user says clients sometimes have trouble downloading the app, leaving some paperwork on paper and some electronic.