How to Import Leads Into Close From CSV: Prepare, Verify, Then Import

Before you import a CSV of leads into Close, verify the emails, then decide how each row maps to a lead and a contact. A CRM is only as useful as its data. A list full of dead addresses means bounced sequences, reps working leads that cannot be reached, and a database nobody trusts. This post is the preparation, in order.

Format your file for Close →

Why verify before the import, not after

Once records are in a CRM, cleaning up is slow. Reps have notes on them. Sequences have started. Reports count them. Before the import, a bad row is one deletion.

There is a second cost: sales teams email from the CRM. If your team sends sequences from connected inboxes, a stream of bounces damages the mailboxes your reps use for real conversations. Our guide to verifying emails in Close CRM covers records already in the account, and email validation on Close forms covers new sign-ups.

Step 1: Decide the shape of the file

Close is organised around leads with contacts underneath. Before you edit anything, decide which of these your file is:

Your file	One row is	What to check
A list of companies with one contact each	A company and its contact	Company name column is filled and consistent
A list of people at many companies	A person	Several rows share a company name spelled identically, so they group
A list of companies only	A company	No email column yet, so skip verification until you add one

Spelling variations such as Acme Inc and Acme, Inc. can create two leads for one company. Standardise company names before the import. Then confirm the mapping on Close's own import screen. We do not state exact header names here because they belong on that screen, not in a blog post.

Step 2: Tidy the file

• Header row in row one, plain names such as email, first_name, last_name, company, phone, title.
• No merged cells or formulas. Export as CSV.
• UTF-8. Fix garbled characters in CSV if accents are broken.
• Phone numbers as text with country codes, because reps will dial them. See clean phone numbers in CSV.

The Close lead import file formatter tidies the headers in your browser.

Step 3: Remove blanks and repeats

• Remove duplicate emails.
• Remove blank rows.
• Count how many rows lack a phone number, a title or a company. Reps notice these gaps immediately.

If your list came from an export of another CRM, export Zoho CRM or Close contacts as a clean list covers the round trip.

Step 4: Verify every email

Upload the cleaned file at /verify. SimpleVerifier runs real SMTP mailbox checks, not just syntax, and flags catch-all, disposable and role addresses.

Result	Meaning	What to do in Close
Valid	Mailbox accepted the check	Import normally
Risky	Often a catch-all domain	Import with a tag, keep out of the main sequence
Invalid	Mailbox or domain does not exist	Do not import as emailable contacts

For invalid rows, think about whether the lead is still worth keeping for calling. A company with a good phone number and a dead email address is still a lead. Import it without the email, or with the email in a note field, so no sequence can send to it.

Catch-all domains accept every address at the SMTP step, so no verifier can confirm one mailbox there. See catch-all emails: what to do.

Step 5: Import and confirm the mapping

On Close's import screen:

1. Map each column and read the preview.
2. Check that the email and phone land in the contact's fields.
3. Check how the import treats records that may already exist, as Close describes it on screen.
4. Add a source and date through a custom field or tag, such as import-2026-11-09.

Import a handful of rows first, open them, and check the leads and contacts look right before you import the rest.

Step 6: Keep the proof of verification

Add a custom field such as email_verified_on with the date. In six months, when someone asks whether a list is stale, you will have the answer. The email list decay calculator gives a sense of how fast a list ages.

Where your lead files come from

• Scraped or finder lists have good coverage but uneven company names. Standardise them.
• Event badges and forms carry typos. Verification catches gmial.com.
• Old exports are the riskiest. Re-verify, always. See find which list source caused bounces to compare sources after a campaign.

The cost of checking every file

SimpleVerifier Pro is $39 a month (or $390 a year), with the first 100,000 checks a month at full speed, then slower, never cut off. Per the pricing page, Pro also includes:

• CSV upload, up to 100,000 rows per file
• Real SMTP mailbox checks, not just syntax
• Catch-all, disposable and role-address detection
• Export valid, risky or invalid separately
• An email finder and website enrichment
• API: 10,000 calls a month included, then $1.50 per 1,000

Only email verification has the 100,000 full-speed fair-use line. The finder and API are not unlimited. We do not publish accuracy percentages. Try a sample of your own file.

Pre-import checklist

1. Decide whether rows are people or companies.
2. Company names standardised.
3. Plain headers, header row first.
4. Duplicates and blanks removed.
5. Emails verified. Invalid out, risky tagged.
6. Mapping and preview checked in Close.
7. A few rows imported first.
8. Source and date recorded.

Quick answers

• Will Close verify emails for me? Check inside your account for what it offers. Verifying the file first works regardless.
• Should I verify phone numbers too? SimpleVerifier Pro includes phone format checks, not a live line check. Live lookups are in the phone add-on.
• How often should I re-verify the CRM? Before any large outbound push, and on a regular schedule for long-lived lists.

Try it on your own list

Upload the file at /verify. The first 100 checks are free with a Google sign-in, no card.

Pro, $39 a month: Unlimited email verification.* Never metered, never cut off. See pricing.

*Fair use: the first 100,000 checks a month at full speed, then slower, never cut off.