Completion day ends with signatures, a funds flow and a lot of relief. Two years later, when the buyer writes to say a customer contract was not what it seemed, the only thing that matters is whether anyone can prove what was in the data room on the day the deal signed. That proof is the archive, and it is built in the week after completion, not in the middle of a dispute.
What is a completion bible, and how is it different from the room archive?
The two are related but not the same, and conflating them is a common mistake.
The completion bible is the lawyers’ record of the transaction itself: the sale and purchase agreement, the disclosure letter, the tax deed if there is one, board minutes, stock transfer forms, resignations and appointments, ancillary agreements, and anything else signed or delivered at completion. It is usually compiled by the buyer’s solicitors, indexed, and circulated to the parties.
The room archive is a snapshot of the due diligence: everything the buyer and its advisers could see before signing, plus the questions they asked, the answers they got and a log of who opened what. It matters because, in a typical UK share sale, the disclosure letter deems some or all of the data room contents disclosed against the warranties. If that is the deal you signed, the archive is the evidence of what the buyer knew.
On most deals today the two travel together. The bible references the archive, often listing it as a schedule or an attachment, and both sets of solicitors keep a copy.
| Item | Completion bible | Room archive |
|---|---|---|
| Signed SPA, disclosure letter, tax deed | Yes | Sometimes, if uploaded |
| Board minutes and completion deliverables | Yes | Rarely |
| Diligence documents as at signing | Referenced | Yes, in full |
| Data room index with document numbers | Often attached | Yes |
| Q&A log with dates and recipients | Sometimes | Yes |
| Audit trail of user activity | No | Yes, if exported |
| Usual compiler | Buyer’s solicitors | Seller’s adviser or solicitors, with the provider |
Why does the archive need more than the documents?
Because a folder of PDFs proves only that those PDFs exist. It does not show when a document was added, whether it was replaced later, which bidder could see it, or that a particular question was asked and answered before signing.
In a warranty dispute, the questions are almost always about knowledge and timing. Was the customer’s termination notice in the room before signing? Did the buyer’s accountants open the management accounts that showed the decline? Was the answer to question 147 given on Tuesday or after exchange? The index, the Q&A log and the audit trail answer those questions. Most data rooms export all of them; some only if you ask.
This is also why the archive should be taken from the room itself, not rebuilt from someone’s local download folder.
How do you archive a data room after completion?
The sequence below assumes a sell-side room on a UK share or asset sale. Adapt the timing if your SPA deems disclosure at exchange rather than completion.
Agree the archive terms before signing
Decide the format, who receives a copy, who pays for any extension and when the room will be deleted. Put it in the engagement letter or a short side note between the solicitors.
Freeze the room at the agreed moment
Stop uploads and set all users to view-only at signing or completion, whichever the disclosure letter refers to. Note the exact date and time.
Export the full set together
Request the documents with their index numbers, the Q&A log with dates and recipients, and the full audit trail. Check that the index in the archive matches the one referenced in the disclosure letter.
Write it to encrypted media
Most providers deliver an encrypted download or an encrypted drive. Store the password separately from the media and record who holds each.
Verify the copy
Open a sample of files from different folders, search the Q&A log, and confirm the file count matches the room. Keep a short note of the check.
Distribute to the agreed holders
Normally the seller's and buyer's solicitors each receive a copy. Record delivery in the completion bible or a covering letter.
Close access
Disable every external user, including advisers, then internal users. Confirm that losing bidders have returned or destroyed material under their NDAs.
Get written confirmation of deletion
Ask the provider to delete the room and confirm in writing when it has done so, including backups within its stated retention cycle.
Where the room archive goes after completion
Final room archive
Files, index, Q&A log, audit trail
Seller's solicitors
Full archive, to defend warranty claims
Buyer's solicitors
Full archive, with the completion bible
Individual sellers
Own copy, until claims periods pass
Corporate finance adviser
Per its own records policy
Losing bidders
Nothing: return or destroy under the NDA
Data room provider
Deletes the room, confirms in writing
Both sides' solicitors keep the full record; losing bidders keep nothing, and the provider deletes.
datarooms.ukAfter completion
Who should keep a copy, and why?
The diagram above shows the usual pattern on a UK private sale. Each holder has a different reason for keeping the archive and a different time horizon.
Seller’s solicitors hold it to defend the seller against warranty claims. If the disclosure letter deems the room disclosed, the archive is the seller’s main shield.
Buyer’s solicitors hold it so the buyer can show what was and was not disclosed if it needs to bring a claim. Their copy normally sits with the completion bible.
The sellers themselves, particularly individual shareholders who have left the business, should keep a copy or at least know where one is. A solicitor’s file may not be easy to retrieve years later.
The corporate finance adviser keeps what its own regulatory and retention policies require. If it is authorised by the FCA, those rules may apply to some of its records; it will know its own position.
Losing bidders should keep nothing. Their NDAs usually require them to return or destroy confidential information when they withdraw, and a short written confirmation is worth asking for.
The provider should delete everything once the archive is delivered, and confirm it. Under UK GDPR it is normally a processor acting on your instructions, and the ICO’s guidance for organisations is clear that personal data should not be kept longer than needed.
How long should you keep the archive?
As long as anyone might need to rely on it, which is longer than most people assume.
The sale agreement sets contractual time limits for warranty and indemnity claims. They are usually shorter for general warranties and longer for tax, and they vary from deal to deal, so read your own SPA rather than assuming a standard.
Behind the contract sits the Limitation Act 1980. Broadly, claims for breach of a simple contract must be brought within six years, and claims on a deed within twelve, although there are exceptions, for example for fraud or concealment. If the SPA was executed as a deed, that longer period may be relevant.
Tax records have their own rules. Companies must generally keep accounting records for six years from the end of the financial year they relate to, as GOV.UK explains, and the target’s own records stay with the company after a share sale.
| Holder | Typical reason to keep it | Practical guide |
|---|---|---|
| Seller’s solicitors | Defending warranty claims | At least until the last claim period under the SPA has expired, and often in line with limitation periods |
| Buyer’s solicitors | Supporting warranty or indemnity claims | As above, alongside the completion bible |
| Individual sellers | Knowing what was disclosed | Until all claims periods have passed |
| Corporate finance adviser | Its own records policy | Per its regulatory and internal rules |
| Data room provider | None after delivery | Delete and confirm in writing |
| Losing bidders | None | Return or destroy under the NDA |
There is a tension here with UK GDPR’s storage limitation principle. An archive full of payroll files and customer data cannot be kept forever simply because it might be useful. The usual answer is to keep it, securely and with restricted access, for as long as there is a genuine legal reason, record that reason, and then delete it.
What format should the archive be in?
Agree this before completion, because the options differ in cost and in how useful the archive is years later.
Encrypted download. The provider packages the room as an encrypted file. Quick, cheap, and easy to copy to more than one holder.
Encrypted drive. A physical encrypted USB drive or similar, sometimes delivered by courier. Good for an offline record, but drives fail and passwords get lost, so keep two.
Read-only extension. The room stays online in view-only mode for a period after completion. Convenient for post-completion integration work, but it is a running cost and a continuing exposure. Agree who pays and when it ends.
Whatever the format, check that the archive opens without the provider’s software, that file names and folder structure match the index, and that the Q&A and audit trail are in a readable format such as PDF or a spreadsheet. If your team uses a different room on the next deal, you still need to open this archive in five years.
Comparing rooms for your next mandate? See how each one handles exports, audit trails and closing a deal.
Compare UK data roomsWhat goes wrong most often?
A handful of mistakes account for most archive problems.
- No freeze. Documents are added or replaced after signing, so the archive does not match what the buyer actually saw.
- Files only. The Q&A log and audit trail are not exported, and the room is deleted before anyone notices.
- Index mismatch. The disclosure letter refers to an index that was later renumbered.
- One copy. Only the seller’s adviser kept the archive, and it changed firms.
- Room left open. Former bidders and departed advisers can still log in months later, and the bill keeps running.
- Lost password. The encrypted drive is in a safe, but nobody wrote down where the password is.
All of these are cheap to avoid in the week after completion and expensive to fix later. Law firms that run many matters often turn the steps above into a standard closing checklist; our law firms page covers how rooms fit a firm’s wider matter management.
Questions people ask
What is a completion bible?
It is the indexed set of signed documents and deliverables from a transaction, usually compiled by the buyer's solicitors after completion. On a deal run through a data room, an archive of the room is normally kept alongside it.
Should the data room archive include the Q&A and audit trail?
Yes. The documents alone do not show when files were added, who saw them or what questions were answered before signing. Those records matter most in a warranty dispute.
How long should a UK deal archive be kept?
At least until all claim periods under the sale agreement have expired, and often in line with limitation periods under the Limitation Act 1980. Balance this against UK GDPR's storage limitation principle and record your reason.
Who gets a copy of the data room archive?
Normally the seller's and buyer's solicitors each receive one. Individual sellers should also keep or know where to find a copy. Losing bidders should return or destroy what they have under their NDAs.
Does the data room provider delete our data after the deal?
It should, on your instruction. Ask for deletion once the archive is delivered and verified, and get written confirmation, including how backups are handled.