Carta built the category, and for years it was the default choice for good reason. Today, a lot of founders are questioning that default. They’re tired of pricing that punishes growth, an interface that requires insider knowledge to navigate, and a support team that’s hard to reach when something actually matters.
Mantle is one of the more compelling alternatives with flat-rate pricing, unlimited stakeholders, native Canadian support (rare in this space), and a white-glove migration process that most founders say takes less than a week. This guide walks you through exactly how to make the switch, what to watch out for, and how to think about the transition so nothing falls through the cracks.
Before You Begin: What You’ll Need
Before kicking off the migration, gather the following:
- Access to your Carta account with admin permissions
- A list of recent transactions not yet reflected in Carta
- 30 minutes of uninterrupted time for the export step
Which path are you on?
- Self-Serve: Export your Carta data and use Mantle’s AI assistant (Clerk) to build your cap table yourself.
- Concierge Onboarding: Grant Mantle admin access to your Carta account, and we’ll handle the migration end-to-end.
Path A: Self-Serve
If you’re on Mantle Starter, you’ll export your data from Carta and use Mantle’s AI features to build your cap table.
Step 1: Export Your Data from Carta
Log into Carta and navigate to your cap table.
- Go to Essentials → View Cap Table
- Select Export
- Choose Securities Ledger by Type and Class
Download your cap table export and all other legal documents (PDFs), including:
- Incorporation documents
- Stock purchase agreements
- Signed SAFEs and convertible notes
- Option plan documents
- Grant agreements
You’ll also want to grab a screenshot of your current vesting schedule templates for easy migration.
Step 2: Sign Up for Mantle
Head to withmantle.com and create an account.
Mantle Starter is our free plan, so it’s great for early-stage companies since it still includes all of the core cap table features. Mantle Essentials and Mantle Growth are our paid plans, which include concierge onboarding (more details below in Path B).
Step 3: Chat with Mantle Clerk
Clerk is Mantle’s AI Assistant, and it can help guide you through building out your cap table.
Let Clerk know you’re building out your cap table in Mantle from Carta, and Clerk will walk you through next steps and help execute tasks (like setting up the existing equity plans or creating the security drafts in Mantle for you).
Step 4: Use AI Draft, Bulk Draft, or Import
If you don’t want to use Mantle Clerk, you can use tools like Mantle’s AI Draft, Bulk Draft, or Bulk Import. AI Draft will read your legal documents and populate your cap table for you. You’ll have the opportunity to review each entry as it’s generated and make any edits before manually publishing.
For importing data manually, the Import feature allows you to download and populate an Excel template, which can then be uploaded to create multiple issuances at once.
Step 5: Review and Reconcile
Once your cap table in Mantle is built, we recommend running a side-by-side comparison between your Carta cap table and your Mantle cap table.
Check for things like:
- Total shares outstanding and authorized shares
- Fully diluted share count (including unissued option pool)
- Each stakeholder’s holdings: share count, share class, and ownership percentage
- Vesting schedules: start dates, cliff dates, total vested and unvested per grant
- Option exercise prices
- SAFE and note conversion terms
You can also ask Clerk to review your cap table in Mantle and flag any issues it finds.
When in doubt, your original legal documents are the source of truth. Have your law firm review the completed cap table before you proceed.
Step 6: Invite Your Stakeholders
Once your cap table is verified, you can go ahead and invite your stakeholders. Mantle Starter includes unlimited stakeholders, so add co-founders, employees with equity, advisors, investors, and legal counsel.
Step 7: Cancel Carta
Once the following are complete, you’re safe to cancel:
- Your Mantle cap table has been reviewed and approved by your attorney
- All stakeholders have received and accepted their Mantle invites
- You’ve downloaded and archived your Carta data exports
- Any pending Carta transactions have been completed
Contact Carta’s support to cancel, and download everything before you do.
Path B: Concierge Onboarding
If you’re on Mantle Essentials or Mantle Growth, our concierge onboarding service is included. Here’s how it works.
Step 1-2: Export Your Data from Carta and Sign Up for Mantle
Follow the same two steps as above, which involves exporting your data from Carta and signing up for either of Mantle’s paid plans.
Step 3: Upload to the Data Room
Upload your Carta cap table export, all PDF agreements, and a screenshot of your current vesting schedule templates.
Once you’ve uploaded all files, click Ready for Review.
Step 4: Mantle Builds and Verifies Your Cap Table
Once we have access, your onboarding team will:
- Import your full transaction history
- Map all security types (common stock, preferred stock, options, SAFEs, convertible notes, warrants)
- Reconstruct vesting schedules for each outstanding grant
- Flag any discrepancies between your Carta data and your underlying legal documents
- Present you with a completed cap table for your review
Most migrations complete within 1–5 business days, though larger and more complex cap tables may take longer.
Step 5-7: Review, Invite, and Cancel Carta
Follow the same steps as the previous section.
Common Questions
Can I keep using Carta while Mantle sets up my cap table?
Absolutely. Your Carta account can stay active and untouched throughout the migration process. We recommend waiting until your Mantle cap table is fully set up before cancelling your Carta subscription.
Do I need to involve my law firm?
You don’t need a law firm to run the migration, but if you do work with one, it’s worth having your attorney/paralegal do a review of the completed Mantle cap table before you cancel Carta.
Can I upgrade from Starter to a paid plan mid-migration? Yes. If you start on Starter and realize you’d rather have Mantle’s team handle it, you can upgrade and the onboarding team will take over from where you are.
Final Thoughts
Migrating a cap table isn’t the most glamorous founder task, but it’s one of those things that pays dividends over time, especially heading into fundraises, secondary transactions, or a liquidity event, where clean, portable, well-documented equity records matter enormously.
Whether you hand it off to Mantle’s team or self-serve with AI Extract, the Carta-to-Mantle path is well-worn. Most founders are fully transitioned within a week.
Have questions about your specific situation? Mantle’s support team is reachable directly and responds quickly, which is, frankly, part of why people switch.