Switching cap table platforms sounds scarier than it is. Your cap table is one of the most sensitive documents in your company, so it’s reasonable to be careful. But “careful” doesn’t mean “hard.” It means knowing what to check, who to notify, and what not to cancel until you’re sure it’s the right time.
Here’s the checklist we walk founders through every time.
Before you migrate: know what you’re actually moving
Your cap table isn’t just a spreadsheet of names and share counts. Before you touch anything, make sure you have clean copies of:
- Every option grant and its vesting schedule
- SAFEs, convertible notes, and their conversion terms
- 409A valuation reports (including historical)
- Board consents and approvals tied to equity events
- Your option pool size and any board-approved increases
- Any outstanding e-signature requests still in progress
If any of this only exists in your old platform and nowhere else, export them now and save them in a secure place.
Timing matters more than most founders expect
There’s a good time to migrate and a bad time. Here are some times to avoid switching:
- Mid-fundraise. Wait until a round closes before moving your cap table.
- Right before a 409A refresh. It’s probably best to get the current valuation finalized on your existing platform first, then migrate.
- The week of a board meeting. Give yourself a buffer so you’re not explaining a platform switch and presenting board materials in the same conversation.
The best windows are usually right after a board meeting, right after a 409A refresh, or at a natural lull between fundraising cycles.
Notify the right people, in the right order
Not everyone needs to hear about a cap table migration the same way.
- Your board. Tell them before it happens. A short note is enough: what you’re switching to, why, and when they should expect it to be live.
- Auditors and legal counsel. If you have external counsel or an auditor who references your cap table, loop them in early. They may want to reconcile the final export from your old platform against what lands on the new one.
- Employees and other option holders. This is where founders most often overcomplicate things. Most stakeholders don’t need details about the migration itself, they need reassurance that their grants are unaffected. A short, plain-language note usually covers it: “We’re moving cap table platforms. Your grant, vesting schedule, and exercise rights are unchanged. You’ll get a new login by [date].” In Mantle, you can send invites to stakeholders to view their holdings from the platform directly.
- Investors. A brief FYI is enough for most. If you have a major investor who actively uses your old platform’s stakeholder/investor portal, give them specific notice of when their access changes.
Run a verification period before you cancel anything
Once your data lands on the new platform, don’t cancel the old one yet. Give yourself a short overlap window to:
- Reconcile total shares outstanding, fully diluted shares, and option pool numbers against your last known-good export
- Spot-check a sample of individual grants, especially anyone with amendments, accelerated vesting, or early exercise
- Confirm 409A history transferred correctly, this is the one document set that’s genuinely painful to reconstruct from scratch
- Get sign-off from whoever owns your cap table internally (often your CFO, finance lead, or the founder who’s been tracking it) before you consider the migration final
Before you cancel your old subscription, check for the following things
This is the step founders skip and regret. Before you cancel:
- Download a final, complete export of your cap table
- Save every historical 409A report as a standalone file
- Confirm there are no outstanding e-signature requests still pending on the old platform
- Check your contract for a required notice period or auto-renewal date
- Save a copy of your full audit trail or activity log if the platform offers one (useful for future diligence or disputes)
Once everything is checked, you’re good to cancel.
After the migration: close the loop
Send one short, final note to your team and board confirming the migration is complete and everything’s verified. It doesn’t need to be long. It just needs to exist, so nobody’s left wondering whether the switch actually finished or whether their equity is sitting in limbo somewhere.
Take advantage of Mantle’s concierge onboarding service with Mantle Essentials or Growth plans.
FAQs founders ask before switching
Will my employees need to re-sign anything?
No, in most cases. Existing grants, vesting schedules, and exercise rights carry over as-is, they don’t need new signatures just because the underlying software changed. If Mantle handles your migration (concierge onboarding is included on all paid plans), our team reconstructs your historical grants directly, so there’s nothing for option holders to re-sign or re-confirm.
What happens to my 409A during the switch?
Your existing 409A valuation stays valid, migrating platforms doesn’t reset it or trigger a new one. Just make sure the full historical report is saved outside your old platform before you lose access in case you need them for an audit later.
Will there be a gap where nobody has access to the cap table?
There shouldn’t be if you sequence it right. Verify your new platform is full populated and confirmed before cancelling the old one. With Mantle, your team gets dedicated support during the transition, so you’re never stuck waiting without an answer.
Can I migrate in the middle of a fundraise?
It’s possible, but we’d generally recommend against it unless you have no choice. Migrating mid-round adds a variable your investors don’t need during diligence. If you have to migrate anyway, tell your new provider exactly where you are in the round. Mantle’s migration team has handled this before and will build the timeline around your close.
What if my existing cap table has errors or inconsistencies?
This is more common than founders expect, and it’s actually a good reason to migrate carefully rather than avoid it. A real migration should surface these issues rather than copy them forward. Mantle’s onboarding team reconciles your historical data line by line and flags anything that doesn’t add up, rather than just importing whatever your old platform exports.
How long does a migration usually take?
For most seed and Series A cap tables, Mantle completes migration within 5 business days. More complex histories, several rounds, secondary sales, may take a bit longer. Either way, the reconstruction work happens on our end, so you won’t need to worry about doing any of the work.
What if I switch and later want to leave Mantle too?
You can export your full cap table at any time, in full.
Related resources:
How to Migrate Your Cap Table from Carta to Mantle
Mantle: The Flat-Rate Pulley Alternative for Growing Cap Tables