What Mercury data does Well pull into Pennylane?

Mercury streams transactions, wires, ACH transfers, card payments, and counterparty records to Well over its MCP server. After Well resolves the counterparty and assigns a confidence score, the matched record posts to Pennylane as supplier and customer invoices via email-in, with amount, VAT, and date pre-filled by Pennylane's OCR, with the Mercury event ID preserved on the entry for audit.

What happens to historical Mercury data when I first connect to Pennylane?

Mercury exposes the last three years through its API on a connected account. The window Well actually pulls is configurable from the integration settings page; each record is matched against your existing Pennylane ledger, and re-running the backfill is safe because Well tracks the Mercury record IDs and updates existing Pennylane entries instead of duplicating them.

Does Well handle multi-currency records between Mercury and Pennylane?

Mercury reports a single base currency; Well stores the value verbatim and tags the record so your Pennylane ledger can apply its own conversion rule at posting time. Exchange-rate fields are not synthesised, so the Pennylane entry carries the unchanged Mercury amount and the conversion is owned by the Pennylane accounting policy.

How does Well prevent duplicates when posting Mercury records to Pennylane?

Mercury sends each event with a stable resource ID that Well tracks against the Pennylane ledger. Webhook replays (which Mercury can issue for delivery retries) are recognised by ID and either skipped or used to update the existing Pennylane entry. Distinct records that look similar are caught by Well before posting, with the candidates surfaced in the review queue when confidence is ambiguous.

What happens if a Mercury record fails to post to Pennylane?

When a record fails to post to Pennylane (validation rule, missing field, transient 5xx), Well retries automatically with backoff. Auth failures short-circuit the retry loop and notify the workspace owner; schema rejections are kept on the integration status page with a one-click retry-after-fix action pointing back at the original Mercury record. Nothing silently drops.

How does Well authenticate with Mercury and Pennylane?

Mercury's MCP server handles authorisation directly; Well receives an access token through Dynamic Client Registration and never sees raw user credentials. For the delivery side, Well forwards the reconciled document to your Pennylane email-in address once it clears the matching threshold; Pennylane creates the draft record from it and you confirm and post it. Well holds no write credential to Pennylane. Tokens are encrypted in transit under TLS 1.3. Anything Well holds between Mercury and Pennylane is encrypted at rest and handled in line with GDPR.

Mercury to Pennylane

AvailableNative · MercuryNative · Pennylane

Connect Mercury to Pennylane with Well

Reconcile Mercury transactions and transfers against your open invoices inside Well, then forward the matched documents to Pennylane's email-in inbox for one-click review.

Connect both toolsView all integrations

Mercury

Source

The Mercury integration connects your startup banking to Well via MCP, pulling transactions, balances, and counterparty data into your workspace.

Pennylane

Target

The Pennylane integration creates a bidirectional bridge between Well and your accounting workspace.

Why this pair

Mercury runs in USD on US banking rails; Pennylane runs in EUR for French SMBs.

Connecting them through Well handles the currency conversion, the counterparty resolution, and the matching in one pass inside Well's own ledger. Well matches every Mercury transaction against your existing invoices with the FX rate of the booking date and the original Mercury reference preserved, then forwards the matched document to Pennylane's supplier or customer email-in address so Pennylane creates the invoice with the data pre-filled.

What Well does between Mercury and Pennylane

One-way: Mercury into Well into Pennylane
Sync mode: Real-time MCP push
Events arrive in seconds

Trigger from Mercury

6 events · pick one

Well engine·recipe·When a new transaction posts on your Mercury account

Source

from bank line · live webhook

OVH Cloud SAS

via Mercury

Transaction

When a new transaction posts on your Mercury account

INV-1024 · 22 Apr 2026$1,284.00

Extract

5 fields read from Mercury

5 fields read

CounterpartyOVH Cloud SAS
Booking date22 Apr 2026
Amount$1,284.00
CurrencyUSD
ReferenceINV-1024

Enrich

against your historical record graph

4 fields added

CounterpartyOVH Cloud SAS
Tax idFR22424761419
Ledger account6156 · IT hosting
Match1 candidate invoice

Confidence97%

<55% refused55–85% review≥85% auto-posts

Post

post as supplier and customer invoices

Create a supplier invoice in Pennylane

auto-posted

posted

TypeSupplier invoice
VendorOVH Cloud SAS
Amount$1,284.00
Ledger6156 · IT hosting
Source docattached
Confidence97%

audit linkto Pennylane

Action in Pennylane

1 compatible with this trigger

Create a supplier invoice in Pennylane

Reconcile Mercury transactions to Pennylane ledger lines.

01Featured

Bridge US and FR without CSVs

Connect Mercury banking to Pennylane accounting without the weekly export ritual.

Cross-border close in days

Pre-filled Pennylane drafts with EUR conversion applied keep both jurisdictions current on the same pace.

Accountant-ready draft

Mercury transactions arrive in Pennylane as pre-filled drafts, ready for your accountant to assign and post.

Audit trail intact

Keep the link between Mercury, invoices, and booked entries for compliance reviews.

13 signals and actions across Mercury and Pennylane

When a Mercury account is read
Pulls from the Mercury transactions API. Pulls each Mercury account the workspace holds with its balance, currency, and routing details. Forwarded to Pennylane's email-in with amount, VAT, and date pre-filled by Pennylane's OCR.
Trigger·Account
When a Mercury card charge posts
Pulls from the Mercury transactions API. Captures debit card transactions with merchant and MCC code. Forwarded to Pennylane's email-in with amount, VAT, and date pre-filled by Pennylane's OCR.
Trigger·Transaction
When a wire transfer is sent from Mercury
Pulls from the Mercury transactions API. Tracks outbound wires with beneficiary detail and instruction. Forwarded to Pennylane's email-in with amount, VAT, and date pre-filled by Pennylane's OCR.
Trigger·Transaction
When an ACH payment clears in Mercury
Pulls from the Mercury transactions API. Picks up cleared ACH credits and debits with the company id reference. Forwarded to Pennylane's email-in with amount, VAT, and date pre-filled by Pennylane's OCR.
Trigger·Transaction
When a check is deposited to Mercury
Pulls from the Mercury transactions API. Tracks check deposits with the payer, amount, and clearing date. Forwarded to Pennylane's email-in with amount, VAT, and date pre-filled by Pennylane's OCR.
Trigger·Transaction
When a wire transfer arrives in Mercury
Pulls from the Mercury transactions API. Captures incoming wires with originator, reference, and value date. Forwarded to Pennylane's email-in with amount, VAT, and date pre-filled by Pennylane's OCR.
Trigger·Transaction
When a new transaction posts on your Mercury account
Pulls from the Mercury transactions API. Triggers on every debit or credit posting in a Mercury account. Forwarded to Pennylane's email-in with amount, VAT, and date pre-filled by Pennylane's OCR.
Trigger·Transaction
When a Mercury account's payment details are read
Pulls from the Mercury transactions API. Resolves the account and routing numbers from the Mercury account so a payment instrument can be matched. Forwarded to Pennylane's email-in with amount, VAT, and date pre-filled by Pennylane's OCR.
Trigger·Payment method
Create a supplier invoice in Pennylane
Driven by Mercury transaction events. Well forwards the extracted PDF to Pennylane's supplier inbox; Pennylane creates the supplier invoice with amount, VAT, and date pre-filled.
Action·Invoice

Reference

Field mapping for Mercury → Pennylane

5 fields across 1 record type, open to see the full table.

Transaction fields

5 fields flow from Mercury into Pennylane.

Mercury field	Label		Pennylane field	Label
transaction.amount	Amount	→	amount	Amount
transaction.currency	Currency	→	currency	Currency
transaction.posted_at	Posted date	→	date	Execution date
transaction.bank_description	Description	→	label	Label
transaction.id	Transaction id	→	external_reference	Source id

Connect Mercury and Pennylane in three steps.

1
Connect Mercury
Click Connect with Mercury; Mercury's MCP server handles authorisation through Dynamic Client Registration. Mercury's MCP server registers a read-scoped Well client through DCR; no credential paste, no shared secret.
- AuthConnect
2
Map your accounts
Well discovers Mercury's transactions, wires, ACH transfers, card payments, and counterparty records and the the Pennylane Purchases tab and the customer-invoice collections list. Counterparty proximity, amount, date, and reference drive the match score; lines above 85% post automatically and the rest queue for a one-click sign-off.
- Auto-post above85% confidence
- Overridemanual anytime
3
Connect Pennylane
Click Connect with Pennylane; Well's OAuth proxy handles Pennylane authorisation through Dynamic Client Registration. Pennylane's MCP server registers a write-scoped Well client through DCR; no credential paste, no shared secret.
- AuthOAuth 2.0
- First syncup to an hour

44 agent skills run on Mercury and Pennylane.

Each one answers a question from the data this pair brings in. The required ones return nothing until a source like it is connected.

Needs a source like these

Runway

Know how many months of cash you have at your current burn, with both sides of the division shown.

Cash position

Know how much cash you hold right now, with the accounts counted and the ones left out both stated.

Cost structure

See where your company's money actually goes, no spreadsheets required.

Payment and invoice lookup

Find what payment settled an invoice, or catch every payment that never got one.

Burn rate

Know what you spend in an average month over a window you can see, with the months that carried no spend counted.

Cash forecast

See the settled month-end cash series and where the line goes from the last complete month.

Cash flow bridge

See how the month moved from opening cash to closing cash, with whatever does not reconcile named as its own step.

Missing supplier invoices

See which suppliers owe you paperwork, before your accountant asks.

Assign missing invoices

Put a name on every settled expense that still has no invoice.

Missing invoice sweep

Walk the whole month-end sweep in one prompt.

Close the books

Drive the month-end close from open to sent to your accounting tool.

Categorize your suppliers

Close the category gaps behind your spend before you close a month.

Board pack

The board numbers in one pass, each with its scope and its window stated.

Subscription spend

See what each scheduled supplier costs a month and a year, how it moved, and where your workspaces can save.

Subscription actions

Cancel a subscription, ask for a better price or contest a double debit, with your bank's facts in the email.

Prefill Form 1120

Get page 1 of your 1120 back as a PDF with your own book figures already in the boxes, and a list of every box left for your preparer.

Prefill Form 1099-NEC

Get one 1099-NEC per contractor back as a PDF with your own posted figures already in box 1, and the list of payees you cannot file for yet.

Unposted and blocked

See what in a month has not reached the ledger, and which pile each item sits in.

Check bank and books

Check that your bank and your books match, and re-run what missed rows.

VAT radar

See the net VAT your posted ledger shows for a quarter and which invoices to fix first.

Accounting reports

Read your profit and loss or balance sheet straight from QuickBooks or Xero.

Answers better with these connected

Receivables aging

See who owes you money, and how long they have been sitting on it.

Bills due

See what you owe and when, ordered by due date with a running total.

Rank clients by LTV

Find out what each customer is worth over its whole life, ranked from the most valuable down.

FX exposure

See how much of your cash and receivables sit outside your reporting currency.

Company profile

Everything you know about one company, in one view.

Missing receipts

Find the bills with no paperwork attached, before an auditor does.

Recurring revenue

Know what you can count on earning each month, averaged over real months.

Invoice fetching agents

See exactly which agents would run, before any of them does.

Convert currencies

Turn mixed currencies into one number you can actually audit.

Payables aging

See what you owe your suppliers, and how long each bill has been past due.

Compose a board

The measures you name, arranged on one board that stores the question rather than the answer.

Revenue by customer

See which customers your revenue came from in a period, ranked, with the part you could not place named.

Supplier spend register

See what you paid each supplier over a year, ranked, with the invoices that could not be placed counted beside the total.

Call and claim

Claim a refund or a compensation with the evidence in hand, and know what to say when you call.

Money back

Find the supplier refunds, VAT credits and expense notes still owed to you, with the evidence for each.

Employer cost

Read a month of payslips, or each of several months, and state, per person, gross pay plus the employee deductions and the employer charges the payslip printed, then list the payroll related bills paid from the bank that no payslip carries.

Check contractor status

For each supplier that looks like a freelancer, read the purchase invoices, the payment rail and any contract Well holds, and state the facts a requalification question turns on, next to the papers your country expects you to keep.

Uses them when they are there

Chart of accounts

Read the accounts your workspace posts to, number by number.

Import a statement

Drop a statement you already have, and get its transactions as records.

Connects and checks them

Check your connections

See what is connected, what is syncing, and what is missing.

Build your context graph

Connect your AI apps and your tools, then see your business as one context graph.

Connect your bank

Get the bank feed in, and confirm it is really live.

Tax id chase

The companies you deal with that carry no tax identifier, listed before year end.

Browse all skills

How Mercury and Pennylane stay secure with Well

Well connects to Mercury through its MCP server, which issues short-lived access tokens via Dynamic Client Registration. Well never holds a long-lived Mercury secret; the server refreshes its own tokens on each session. Anything Well holds between Mercury and Pennylane is encrypted at rest and handled in line with GDPR.

MCP server authEncrypted at restGDPR compliant

Scopes Well requestsmcp.mercury.com/mcp

Read Mercury records
Scoped to transactions, wires, ACH transfers, card payments, and related records. No access to anything else in your Mercury account.
granted
Deliver documents to your Pennylane inbox
Well forwards the extracted document to your Pennylane email-in address; Pennylane reads supplier and customer invoices via email-in, with amount, VAT, and date pre-filled by Pennylane's OCR from it and you review and post. No write credential to Pennylane is requested.
granted
Modify or delete Mercury records
Not granted. Mercury is read-only on Well's side; the source of truth never moves.
refused
Read other workspaces' data
Not granted. A session resolves only to the workspaces your account belongs to, and Well checks that membership before it returns any record.
refused

Disconnect any time from Well settings or Mercury’s admin panel.

Frequently asked questions about Mercury and Pennylane on Well

01What Mercury data does Well pull into Pennylane?: Mercury streams transactions, wires, ACH transfers, card payments, and counterparty records to Well over its MCP server. After Well resolves the counterparty and assigns a confidence score, the matched record posts to Pennylane as supplier and customer invoices via email-in, with amount, VAT, and date pre-filled by Pennylane's OCR, with the Mercury event ID preserved on the entry for audit.
02What happens to historical Mercury data when I first connect to Pennylane?: Mercury exposes the last three years through its API on a connected account. The window Well actually pulls is configurable from the integration settings page; each record is matched against your existing Pennylane ledger, and re-running the backfill is safe because Well tracks the Mercury record IDs and updates existing Pennylane entries instead of duplicating them.
03Does Well handle multi-currency records between Mercury and Pennylane?: Mercury reports a single base currency; Well stores the value verbatim and tags the record so your Pennylane ledger can apply its own conversion rule at posting time. Exchange-rate fields are not synthesised, so the Pennylane entry carries the unchanged Mercury amount and the conversion is owned by the Pennylane accounting policy.
04How does Well prevent duplicates when posting Mercury records to Pennylane?: Mercury sends each event with a stable resource ID that Well tracks against the Pennylane ledger. Webhook replays (which Mercury can issue for delivery retries) are recognised by ID and either skipped or used to update the existing Pennylane entry. Distinct records that look similar are caught by Well before posting, with the candidates surfaced in the review queue when confidence is ambiguous.
05What happens if a Mercury record fails to post to Pennylane?: When a record fails to post to Pennylane (validation rule, missing field, transient 5xx), Well retries automatically with backoff. Auth failures short-circuit the retry loop and notify the workspace owner; schema rejections are kept on the integration status page with a one-click retry-after-fix action pointing back at the original Mercury record. Nothing silently drops.
06How does Well authenticate with Mercury and Pennylane?: Mercury's MCP server handles authorisation directly; Well receives an access token through Dynamic Client Registration and never sees raw user credentials. For the delivery side, Well forwards the reconciled document to your Pennylane email-in address once it clears the matching threshold; Pennylane creates the draft record from it and you confirm and post it. Well holds no write credential to Pennylane. Tokens are encrypted in transit under TLS 1.3. Anything Well holds between Mercury and Pennylane is encrypted at rest and handled in line with GDPR.