Sign-and-pay-deposit in one link
Lets solo service providers send one link where the client signs the agreement and pays the deposit in the same step.
The problem
One small-business reviewer describes a two-step routine: the client signs the contract, then the owner sends a separate invoice for the deposit. Another reviewer says every contract tool they tried feels too complex for what they want, which is a signature so the project can start. Each hand-off gives the client a chance to sign and then stall on the deposit.
Who has it: Solo wedding DJs, photographers, event stylists, contractors and consultants who book jobs with a contract plus a deposit.
Who pays
The solo business owner, who wants booked dates to be actually secured and doesn't want to chase deposits after the signature. · $15–25/month flat, or $5 per signed booking
Charge a flat monthly fee, with a free tier of 2 bookings a month. Find first users in wedding vendor, DJ and photographer Facebook groups and subreddits, offering to set up their existing contract template for free.
What to build first
- Upload a PDF or paste contract text, then set a deposit amount or percentage
- Client link with typed or drawn signature and no account needed
- Stripe Checkout for the deposit, unlocked only after signing
- Signed PDF with timestamp and IP, emailed to both parties
- Dashboard showing which bookings are unsigned, signed-unpaid, or secured
- Auto-reminder after 48 hours if either step is missing
Suggested stack
Next.js Supabase Stripe Checkout Resend react-signature-canvas
Starter prompt
Paste it into Cursor, Claude Code, Lovable or Bolt and iterate from there.
Build a web app called BookLock for solo service providers. A provider signs in (Supabase auth), uploads a contract PDF or pastes text, enters a client name, email and a deposit amount, and gets a private no-login link. The client opens the link, reads the contract, types or draws a signature, ticks an 'I agree' box, and is then sent to Stripe Checkout to pay the deposit. Use Stripe Connect Express so money goes to the provider. On payment success, generate a signed PDF that stamps the signer name, timestamp and IP, store it in Supabase Storage, and email it to both parties via Resend. Build a dashboard with three statuses: Sent, Signed-unpaid, Secured. Add a scheduled job that emails the client a reminder 48 hours after sending if either step is incomplete. Keep the UI mobile-first and minimal.What could go wrong
Crowded e-sign market (SignNow, Dropbox Sign, HoneyBook, Dubsado), and Stripe Connect adds compliance work. The evidence here is review text rather than direct requests for this exact tool, so check demand with a landing page first.
Where we found it
- SignNow review: contract then separate deposit invoice — A small-business user has clients sign the contract and then sends an invoice for the deposit as a second step.
- Signaturely review: tools feel too complex — A reviewer says contract and proposal tools always feel complex when all they want is a signature so the project can start.