Moving your bookkeeping to Mercury Books works best as a clean period cutover: you close your last period in your current system, start fresh in Books from a date you choose, and keep your old records for history. This article walks through how to do it.
Before you start
Decide on your cutover date. The first day of a month, quarter, or fiscal year is easiest — reconciliation in Books runs on monthly windows, so a mid-month cutover leaves you with a partial first period.
Then close out your current system through the day before your cutover date, and pull three things from it:
- Your chart of accounts, exported as a CSV
- A trial balance or balance sheet as of the day before your cutover date, so you have your opening balances
- Any reports you want to keep for your records
Tip: Don't close your old subscription until you've pulled everything you need and your first month in Books reconciles cleanly.
Step 1: Bring over your chart of accounts
During setup you can import your exported chart of accounts as a CSV instead of starting from one of Mercury's templates. If your structure in QuickBooks Online or Xero is one you want to keep, this is the fastest way to carry it over.
You can also edit accounts once you're in — add, rename, or remove them from the Chart of Accounts page, or via Command. But the fastest approach is to get your desired chart of accounts in during setup.
Step 2: Update your entry start date
Under Settings > Books Details, update the Start date to the date of your cutover.
You cannot move your entry start date to a date that is later than transactions that already exist in your general ledger. You can move it to an earlier date, and Books will pull in available historical transactions and auto-categorize them for you.
Step 3: Connect your accounts
Connect your Mercury accounts, external bank accounts and credit cards through Plaid, and any Stripe, PayPal, or Gusto integrations you use. Books syncs transactions from your entry start date forward.
See our Connecting accounts and integrations article for the full walkthrough.
Step 4: Record your opening balances
Your opening balances carry your closing position from your old system into Books. Create a journal entry dated the day before your entry start date, using the trial balance you exported:
- Go to Journal Entries
- Click Create journal entry
- Date it the day before your entry start date
- Add a description
- Enter a line for each balance sheet account and its balance, with the offset going to your opening balance equity or retained earnings account
- Confirm your debits and credits balance, then post it
Step 5: Reconcile your first period
Once your transactions have synced and your opening balances are in, reconcile your first month. This is the check that your cutover was clean — if the ending balance matches your statement, you're set.
See our Reconciling accounts in Mercury Books article.
What to do with your historical data
Books doesn't import your transaction history from QuickBooks Online, Xero, or NetSuite. Keep your prior system's records for periods before your cutover date, and export copies of the reports you'll want later — profit and loss, balance sheet, and general ledger for each closed year.
If you do want history inside Books, set an earlier entry start date. Books then syncs the older transactions from your connected accounts, and you categorize them in Books.
FAQs
Will my old transactions come across automatically?
No. Books syncs transactions from your connected accounts starting at your entry start date. It doesn't read data out of QuickBooks Online, Xero, or NetSuite.
Can I keep my old system connected while I try Books?
Yes. See our Using Mercury Books alongside another accounting system article for what changes when you do.
Will my categorization rules come over?
No. Rules in Books are built against your Books chart of accounts, so you set them up fresh. See our Managing categorization rules article.
Mercury is a fintech company, not an FDIC-insured bank. Banking services provided through Choice Financial Group and Column N.A., Members FDIC.