How to Connect ChatGPT to LedgerMCP with MCP

Connecting ChatGPT to LedgerMCP turns ChatGPT into a working bookkeeper. It can import bank statements, categorize transactions, reconcile accounts and run a P&L inside real double-entry books. LedgerMCP (built by eSEOspace) hosts the server, so there is nothing to install.

Checked against: LedgerMCP's docs on 28 October 2026. eSEOspace built LedgerMCP.

We also checked the ChatGPT side against OpenAI's help page on custom MCP servers on the same day, because its current steps differ from older guides.

Before you start

You need two accounts:

• A LedgerMCP account. The pricing page lists a Free plan at $0 with unlimited books, all reports and "your own AI over MCP." Paid plans (Starter $9, Growth $39, Scale $249 a month) add live bank feeds. You can also create the account during the ChatGPT sign-in, because new accounts "are free and created instantly," per LedgerMCP's ChatGPT page.
• A ChatGPT plan that allows custom MCP servers. OpenAI's page says these connections are "available for ChatGPT Business and Enterprise/Edu customers on ChatGPT web." Its FAQ adds that Pro users can connect custom MCP servers "with read/fetch permissions." Bookkeeping writes, such as categorizing a transaction, need full MCP.

Workspace rules matter too. In a Business workspace, OpenAI says only admins and owners can create and publish plugins for custom MCP servers. In Enterprise/Edu, admins can grant other members the right through role-based access control (RBAC). The workspace permission is named Create plugins with MCPs.

Custom MCP servers can't be added on mobile. OpenAI's FAQ answers that question with "No - web only."

Steps

These steps follow OpenAI's current Plugins flow, with LedgerMCP's address and sign-in from LedgerMCP's docs.

1. In ChatGPT on the web, go to Plugins.
2. Select the plus button, then select Add custom MCP server.
3. Enter a name, such as LedgerMCP, and optionally a description.
4. Under Connection, enter the server URL:

https://ledgermcp.com/mcp

1. Set up authentication with OAuth, which LedgerMCP's docs name as the preferred method. You don't need a client ID or a key.
2. Review the risk warning and select the I understand and want to continue checkbox.
3. Select Create as a plugin, then review the discovered tools and metadata.
4. When ChatGPT opens LedgerMCP's sign-in, enter your email and the 6-digit code from your inbox.
5. Install the plugin, start a new conversation, type @ and select LedgerMCP.

In a Business or Enterprise/Edu workspace, an admin or owner then publishes the connection so other members can use it. OpenAI's page describes the path: Admin Console, the workspace, Plugins, Manage Legacy Apps, Drafts, then Publish.

OpenAI's page also keeps a "legacy custom app configuration" (Apps > Create in workspace or user settings, then Scan Tools). It ties neither flow to a different plan: both sit under the same Business and Enterprise/Edu rules. LedgerMCP's own ChatGPT page still describes an older Developer mode route under Settings, Connectors. Either way, the inputs are the URL above and your email sign-in.

Check that it works

LedgerMCP's llms.txt tells a connected agent to call list_businesses first, then read list_conventions and list_questions. A good first prompt does exactly that.

Example prompts:

• "@LedgerMCP list my businesses and show any open questions you've parked for me." (list_businesses, list_questions)
• "Import this June statement CSV into Business Checking and categorize what you're sure of." (import_transactions, bulk_categorize)
• "Run my P&L for last quarter and compare it with the quarter before." (run_pnl with period comparison)

If the first prompt returns your books, it works.

Permissions and safety

LedgerMCP enforces its rules in the database, not in the model. The llms.txt file lists them:

• Every entry balances. An unbalanced write is rejected at commit.
• Postings are immutable. There is no edit and no delete. Corrections are linked reversals through reverse_entry.
• Retries are safe. Posting writes need an idempotency key, and replaying a key returns the original entry.
• Some actions are human-only. Deleting transactions, deleting accounts, deleting receipts and disconnecting a bank happen only in the web app.
• Lock dates belong to the owner. If a post is refused because the period is locked, the agent is told to say so and stop.

The docs mark 4 tools destructive: update_bank_account (which can merge two accounts), undo_import, resolve_duplicate and reverse_entry. Even these keep the history, because reversals post new entries.

On the ChatGPT side, OpenAI's app permissions page lists Always ask, Allow read actions, Allow low-risk actions and Allow all actions. For books, Always ask or Allow read actions is a sensible start. Avoid Allow all actions, which OpenAI says "carries elevated risk."

Before you connect any finance tool, read the MCP Security Center and our guide to MCP permissions and approvals.

If it doesn't work

• No Add custom MCP server option. OpenAI limits custom servers to Business and Enterprise/Edu, with read/fetch-only access on Pro. In a workspace, ask an admin for the Create plugins with MCPs permission.
• Writes fail on Pro. That matches OpenAI's FAQ: Pro gets read/fetch permissions only, so reports work but bookkeeping writes need full MCP.
• "Disabled by admin" or "Admin approval required." OpenAI's troubleshooting page says to ask a workspace admin to review the plugin and its app.
• Tools look out of date. OpenAI says a published workspace connection uses a "frozen" snapshot of tools until an admin refreshes and republishes it.
• The sign-in keeps expiring. OpenAI notes that OAuth without refresh tokens may force users to reauthenticate. Sign in again with a new 6-digit code, and contact support@ledgermcp.com if it repeats.
• A post is refused for a locked period. That is by design. Only the owner can move the lock date.

Next step

Once ChatGPT is connected, read the LedgerMCP server profile for the full tool groups, or see how the product was built in our LedgerMCP client spotlight. For other clients and apps, browse the connect guides.

Frequently asked questions