Industries

How can a collections team check phone numbers and emails on an account list?

Run the contact details on each account through a numbering-plan check, a carrier-block lookup and an email domain check before an agent works the file. The results are facts about the number and the domain, and your team decides what to do with them.

The problem

Collections work depends on contact details that were captured long ago. Numbers have extra digits or missing country prefixes, emails sit on domains that no longer receive mail, and the list owner often cannot say which rows were ever tested.

Every wasted attempt costs an agent minutes, and a wrong or malformed number can point a call at someone who has nothing to do with the account. Teams want to know which rows are well formed before the work starts, and to keep a record of what each check returned.

The checks need to be plain and repeatable. A lookup that returns formatted numbers, a number type and a domain verdict in a fixed shape is easy to run across a portfolio and easy to explain to whoever reviews the file later.

The CFPB received approximately 387,400 debt collection complaints in 2025. 2025. CFPB Consumer Response Annual Report, 2025, read 2026-10-18.

What LookValid does for this

LookValid products for Debt collection
Check	What it gives you	Credits
Standardize every number	Parses each number against its country numbering plan and returns E.164, national and international formats with the number type the plan assigns. It is a numbering-plan check: it cannot tell whether the line is active or who holds it.	1 credit per valid number
Add the block holder for US numbers	Returns the carrier originally assigned the number block with its rate center and state, from public NANPA reports. Ported numbers still show the original carrier.	1 credit per lookup (numbers outside the covered numbering plan areas are free)
Check the mail domain	Reads MX, SPF and DMARC for the domain and flags disposable domains, free providers and role mailboxes such as an info mailbox. It never contacts the mail server, so it cannot confirm that a particular mailbox exists.	1 credit per address checked
Look at when a business domain was registered	For business accounts with a website, returns registration, update and expiry dates and the registrar from the public RDAP service, so an analyst can see how long the domain has existed.	2 credits per registered domain (unregistered domains are free)

A real request and response

This request checks the domain behind one address from an account file. The response lists the MX and policy records found and the flags for disposable, free and role addresses.

POST /v1/email-domain-check

1{
2  "email": "info@example.com"
3}

Response, captured 2026-10-18

1{
2  "found": true,
3  "data": {
4    "email": "info@example.com",
5    "syntax_valid": true,
6    "domain": "example.com",
7    "mx_records": [],
8    "has_mx": false,
9    "null_mx": true,
10    "implicit_mx": false,
11    "spf": {
12      "record": "v=spf1 -all",
13      "record_count": 1,
14      "policy": "-all",
15      "valid": true,
16      "issues": []
17    },
18    "dmarc": {
19      "record": "v=DMARC1;p=reject;sp=reject;adkim=s;aspf=s",
20      "record_count": 1,
21      "policy": "reject",
22      "subdomain_policy": "reject",
23      "pct": null,
24      "rua": [],
25      "valid": true,
26      "issues": []
27    },
28    "disposable": false,
29    "free_provider": false,
30    "role_account": true,
31    "smtp_checked": false,
32    "deliverability_signal": "undeliverable",
33    "deliverability_reasons": [
34      {
35        "code": "null_mx",
36        "message": "The domain publishes a null MX record, which means it does not accept email."
37      },
38      {
39        "code": "role_account",
40        "message": "The address is a shared role mailbox such as info@ or support@, not a person."
41      }
42    ]
43  }
44}

This is one real run of Email Domain Check against a fixed public input, captured 2026-10-18. Sources: Public DNS (MX, TXT); Open disposable-email-domain and free-provider lists.

Questions

Can it confirm a debtor owns a phone number or an email address?

No. The phone check reads numbering-plan rules and the email check reads the domain only. Neither one says who uses the number or the mailbox, so use them to spot malformed or unusable contact rows, not to confirm identity.

Which numbers can I drop before dialing?

Rows the phone check marks as not possible for their country, and numbers typed in the wrong country format. Toll-free and premium-rate types are labeled too, so you can set those aside. The check reads the numbering plan only and never queries a carrier.

Can I check a whole file of accounts?

Yes. Each lookup is one request for one number, address or domain, so you run it in a loop over your own file and store the results next to each account record.

Sources

CFPB Consumer Response Annual Report, 2025 https://files.consumerfinance.gov/f/documents/cfpb_2025-cr-annual-report_2026-03.pdf, read 2026-10-18

LookValid is run by Meralume Labs. It is not connected to, endorsed by or a partner of any company or product named on this page, and every product name belongs to its owner.

LookValid bills every lookup in credits from one shared balance, so one key covers each check on this page.

See Phone Numbering-Plan Validation