Before anyone calls, emails or works it
You're about to work the list. Check it first.
Datuma checks the contact list you already have, row by row, before your team calls, emails or works it.
For agencies, consultancies and any team handed a list it did not build.
First check free
Start your free check
Up to 300 rows you choose, once per organisation. We walk you through what we found on a fifteen-minute call. No file comes back with the free check.
From the example full check
A change of role or organisation was confirmed in review.
stopped
E. Castellan, Head of Client Development, Pennock Hythe Ltd e.castellan@•••••.co.uk · checked 26 August 2026
The list you did not build goes out as yours.
When it goes wrong, it goes wrong in front of your client.
If someone else built the list you're about to call or send, Datuma checks it before you do.
- Mobile numbers no longer live.
- People who have moved organisation.
- Addresses that do not accept mail.
- The same contact twice.
how a full check works
We do the checking.You are not handed a tool.
- No integration needed.
- No software to learn.
- No rebuilding your file.
The checks run automatically, row by row. A person approves the finished check before it comes back.
What happens to your list
Your list goes in as it is. It comes back separated, with a reason beside every row we stopped.
- 1 · your listas sentyour_list.csvR. AinsworthYarrow Gate Media LtdA. WhitfieldMarlow Ridge Consulting LtdM. DeardenThornbury Lane Group LtdD. KelsallRavensworth Trading LtdJ. MarsdenKestrel Row Foods LtdR. AinsworthYarrow Gate Media LtdR. OkaforAshdon Field Ltd2,400 rows, every one looking the same
- 2 · datuma checks itrow by row
- The email address
- The mobile number
- The person in the role and organisation on your row
- The duplicates
A person approves the finished check. - 3 · what comes backof 2,4002,075 in your working file The file you work from.
- R. Ainsworth
- D. Kelsall
- R. Okafor
303 stopped Each with its reason and the date we checked it.- A. Whitfield
- M. Dearden
- R. Ainsworth
22 protected Kept aside on your protected accounts list. Also in your stopped rows.- J. Marsden
An example. The people and organisations are invented, and the figures are illustrative, not measured.
You can show why each row is where it is.
Row Passport An example. The organisations, people, findings and dates are invented.
D. Kelsall Commercial Director · Ravensworth Trading Ltd Customer record CW-104311 · Datuma row ID DR-WMFW1Q04TF
READY Nothing we found required this row to be stopped. In your working file.
Evidence Email: The address you supplied accepted mail on 26 August 2026.
More than one current role on record Commercial Director at Ravensworth Trading Ltd, from April 2019. No end date recorded. Partner at Halloway Beck Partners Ltd, from June 2026. No end date recorded. Both are listed with no end date on the profile read on 26 August 2026. This does not establish that either role has ended, or that a newer role replaced an earlier one.
Other checks Telephone: No number was supplied. Profile: The profile confirmed as this person records Commercial Director at Ravensworth Trading Ltd, since April 2019. Read on 26 August 2026.
Not established Another role was found, but an end to the role on your row was not established.
More detail: the row as you supplied it, what the profile records, and the update file's codes for this row. Full check of 30 August 2026 · Method version: readiness-r1/2.0.0
the evidence · the row passport
Every Row Passport records what was checked and what came back.
One card per row: the finding it carries, the evidence behind it, and the date we checked where there is one.
Nothing is inferred from an unanswered check.
measured, on our own files
Between 10 June and 21 August 2026, a person looked at 125 flagged changes of role or organisation on our own files. 95 were confirmed. 30 were not, and those rows stayed in.
what makes it different
Not a data vendor, and not another email verifier.
A done-for-you check of the list you already have.
- We never sell the data you send us.When we stop a row, we are not the ones selling you its replacement.
- No ranking and no score in the files.There is no column telling you who to contact first.
- We show what the evidence supports. You decide.Nothing leaves your list silently.
- The free check takes one file of up to 300 rows, chosen by you.
- One check per organisation.
- A person runs it before a fifteen-minute call, and on the call walks you through your own rows.
- You get three numbers: how many would be in your working file, how many were stopped, and how many raised a question, with what we decided. You do not get a file back. The finished files come with the full check.
what it costs
See every price and what it includes Full checks from £450, one flat price set by the number of rows in your file.
- up to 250 rows £450
- up to 1,000 rows £950
- up to 2,500 rows £2,250
- up to 5,000 rows £4,250
- above 5,000 rows Quoted
Everything is included. Paid when you send your file.
If the full check has not found something worth knowing on at least one of the rows in your file, we refund it in full.
10% of everything you pay Datuma goes to Camp Mohawk, a charity day centre for children with special needs.
what comes back
A list to work from, every stopped row with its reason, and the evidence.
Your working file Your columns, in your column order, carrying the rows we did not stop. It is the file you work from.
The stopped rows Every row we stopped, with the reason and the date we checked it. Put any of them back if you disagree. It is your list.
The evidence What we read for each row and the date we checked it, where there is one: a Row Passport for every row, and what we decided on every row placed by a person's review of a possible change of role or organisation.
See everything included in the handover
- 1/7 The list, in the shape it arrived …_working_v01.csv Your columns, in your column order, carrying the rows we did not stop. It is the file you work from.
- 2/7 The update file …_datuma-update_v01.csv One row for every row you sent: the outcome, the reason, the dates and what each channel established, keyed on your own record ID.
- 3/7 The stopped rows …_stopped-rows_v01.csv Every row we stopped, with the reason and the date we checked it. Put any of them back if you disagree. It is your list.
- 4/7 The Decision Brief …_decision-brief_v01.html The rows placed by a person's review of a possible change of role or organisation, with what we decided on each and why. Nothing here needs an answer: your files already reflect every decision.
- 5/7 The changelog …_changelog_v01.csv Every change, every removal, and every difference we found and left in place, with the reason and the date.
- 6/7 The withheld addresses …_withheld-hubspot_v01.csv The addresses kept out of the send, in the shape HubSpot loads.
- 7/7 The Row Passports …_row-passport_v01.html One card per row: the finding it carries, the evidence behind it, and the date we checked where there is one.
- +1 The full check page One private page, by link, carrying the counts, the categories, the dates and the file names.
- Where your data is held and who else is involved: the security page.
- Your own clients, competitors and the organisations you are in a deal with are kept aside on your instruction, with the reason. Included.