Recover the source
Collect old confirmations, statements and tax forms. Ask a former broker for archived records while they remain available. Record what each document proves and where the chain still has a gap.
A lifetime investment ledger
Investment Record Keeping for Taxes: One Complete Record of Every Transaction
Your broker may keep required records for only 3–6 years under SEC Rule 17a-4. Your cost basis may need to survive for as long as you hold an investment, through every broker you will ever use, and beyond the eventual sale.
Statements in a portal are temporary access to somebody else's archive. A continuing ledger keeps your buys, sells, dividends, fees, corporate actions and per-lot cost basis under one history you maintain.
The useful distinction
A ledger remembers what a balance sheet forgets
A current balance tells you what is there now. Tax reporting depends on the chain of events that made it so.
Balance-sheet view
Today's position
AAPL, 120 shares, current value $27,480. Useful for seeing allocation and net worth, but silent about when those shares arrived, which lots were sold, and how fees or reinvestments changed cost.
Ledger view
Every event behind it
Each purchase date, quantity and price; every sale matched to lots; fees, dividends, splits and transfers retained in sequence. AllInvestView is the ledger, while its dashboard gives you the balance-sheet view built from that history.
That difference matters after a transfer, when a feed begins late, or when a tax authority asks how you reached a figure. A folder of PDFs preserves evidence. A ledger also keeps the arithmetic usable.
US and UK guidance
What investment records to keep, and for how long
Keep the source records that establish acquisition, ownership, income and disposal. In the US, that means trade confirmations, brokerage statements, Forms 1099-B, 1099-DIV and 1099-INT, dividend-reinvestment records, fee records and corporate-action notices. For gifted or inherited property, retain documents supporting the relevant fair market value and any donor basis information. A year-end statement alone may not preserve everything needed to establish a particular lot.
The IRS says records supporting an item on a return should remain available until the limitation period for that return expires. The common minimum is three years, but property records must be kept until after the year in which the property is disposed of. The practical rule is therefore: keep basis evidence throughout ownership, then retain it with the disposal-year return for at least the applicable review period. Keep it longer when a loss carryforward, amended return, underreported income or another extended limitation period applies.
In the UK, keep contract notes, account statements, consolidated tax certificates, dividend vouchers, charges, foreign-exchange evidence and every notice for a split, rights issue, takeover or other reorganisation. HMRC's HS284 explains the share-matching sequence: same-day acquisitions, acquisitions within the following 30 days, then the Section 104 holding. One missing purchase can change the pooled average cost of shares you still hold, so the history matters before any disposal is made.
For an on-time Self Assessment return, UK records not connected with self-employment normally need to be kept for at least 22 months after the end of the relevant tax year. Records supporting a capital gains calculation must be kept for at least a year after the Self Assessment deadline, and longer if the return was late or HMRC has started a check. Self-employed people must keep business records for at least five years after the 31 January submission deadline. These are post-disposal minimums, not permission to discard purchase records while the asset is still held. A platform's displayed “book cost” is helpful, but the taxpayer remains responsible for the calculation reported to HMRC.
- Keep originals as evidence: confirmations or contract notes, periodic and year-end statements, tax forms and certificates.
- Keep events that alter basis: reinvested dividends, return of capital, splits, spin-offs, mergers, rights issues and fees.
- Keep context: account and currency, original quantity and price, exchange rate used, and transfer-in or transfer-out dates.
- Keep exports before access changes: download records before closing an account or losing online access.
Primary references: SEC broker-dealer records rule, 17 CFR § 240.17a-4; IRS record-retention guidance; IRS Publication 550; and HMRC HS284. Tax rules depend on circumstances; this guide is general information, not tax advice.
Start with what exists
Interactive Brokers
Schwab
Fidelity
DEGIRO
Get the full history in, not just today's positions
A new connection may begin with the transactions a broker currently exposes. That can be enough for today's quantity and still leave the oldest lots, transfers or reinvestments outside the record. Build from the earliest available evidence, then continue the same ledger.
AllInvestView gives you three supported paths. CSV import auto-detects 28 broker formats, with a generic CSV path for others. The assistant can read trades from a photo, screenshot or PDF and shows what it found before anything is added. Automatic read-only sync with 30+ brokers is on the paid plans; the connection cannot place trades or move money. Import, manual entry and the assistant work on Free.
Use the method that gives the best evidence for each period. An old CSV can establish the early years, statement photos can fill a small gap, and read-only sync can carry the record forward. Import confirmation is the checkpoint: verify dates, symbols, quantities, prices and currencies before saving.
For broker-specific export instructions, use the investment import guides. If your question is mainly how to view several active accounts together, read how to track multiple broker accounts.
Interactive Brokers
Schwab
Fidelity
DEGIRO
Confirm before changing the ledger
Missing or wrong cost basis starts with the underlying event
Do not patch a current total and leave the history unexplained. Find the earliest place where quantity or cost diverges.
Replay events in order
Enter buys and sells chronologically, then apply dividend reinvestments and corporate actions on their effective dates. A later split or spin-off depends on the quantity and cost immediately before it.
Compare quantity first
Match each holding's units before comparing market value. Once quantity agrees, inspect original trade currency, pence-versus-pounds scale and foreign-exchange treatment rather than overwriting the result.
What the tax return needs
In the US, Form 8949 and Schedule D ultimately depend on acquisition date, disposal date, proceeds, basis and adjustments. Covered-basis reporting from a broker helps, but it does not remove the need to keep supporting records, especially for non-covered securities or events the broker did not receive.
In the UK, HMRC does not receive a broker-calculated Section 104 pool as the answer to your Self Assessment. You calculate allowable expenditure using the share-matching rules. A missing contract note can change the pool for later disposals and shares still held.
AllInvestView keeps per-lot transaction data and lets the assistant propose corrections with a before-and-after view. The edit waits for confirmation. For the calculation methods themselves, use the dedicated FIFO cost basis tracker and investment tax reporting guide. For cross-account reporting, see the multi-broker tax report.
The assistant works on the record with you
Bring in evidence, correct the scale, keep watch
Three interactions already available in AllInvestView: statement import with confirmation, a before-and-after price-scale correction, and a standing alert.
📷 old-broker-statement.pdf
I found 3 trades in that statement. Review them before they are added.
Confirm 3 trades
| Ticker | Date | Qty | Price |
|---|---|---|---|
 VWCE | 14 Mar 2019 | 18 | €72.40 |
 MSFT | 08 Jun 2020 | 5 | $187.20 |
 SHEL | 22 Sep 2021 | 60 | £14.86 |
Before the old login disappears
Switch brokers without losing the history behind your holdings
A securities transfer moves assets. It does not guarantee that every historic detail will appear correctly in the receiving broker's interface. In the US, covered securities generally carry reported basis, yet pre-coverage holdings, average-cost fund elections, fractional transactions and off-market details may need attention. In the UK, the displayed book cost after a transfer can be incomplete or reset, while your own Section 104 calculation continues across the change.
Before initiating a move, export the complete transaction CSV and download every available statement, confirmation or contract note. Record account identifiers and the transfer date. After the move, compare securities and quantities first. Then compare lot-level basis and acquisition dates. Do not discard the old archive merely because the receiving account now displays a plausible total.
A broker-independent ledger keeps both sides understandable. Label the outgoing and incoming accounts, retain the transfer event, and continue adding later transactions to the same investment history. There is no need to merge the brokerage accounts themselves. AllInvestView can track stocks, ETFs and funds, bonds, options, crypto, cash accounts, real estate, and custom assets in one portfolio while preserving which account each transaction belongs to.
If the receiving broker shows an opening position rather than the original lots, use the source records to preserve the earlier purchases in your ledger. Avoid recording the transfer as a fresh taxable purchase or sale unless that is what legally occurred. If acquisition records cannot be recovered, document every request and assumption and ask a qualified tax professional how to report the unsupported portion.
When the numbers do not match
A broker feed is a delivery route, not the history itself
Automated feeds are useful, but they transmit what a provider exposes in the shape it exposes it. A feed may start after your earliest purchase, represent a transfer as an opening balance, or omit a dividend reinvestment or corporate action. Foreign listings introduce another familiar problem: a London price quoted in pence can be read as pounds, producing a value exactly 100× too large.
Treat the ledger as the durable layer. Keep the imported transactions, attach meaning to corrections, and compare feed updates against the established record. When something differs, isolate one holding and work in sequence: opening quantity, buys, sells, reinvestments and corporate actions, then price currency and scale, then market value.
This is why forcing a dashboard total is the wrong fix. It can make today look right while leaving every return and tax figure downstream wrong. A confirmed transaction or scale correction repairs the event that drives those calculations. The permanent record remains understandable even if you disconnect the broker later.
Temporary patch
Overwrite the current balance
The dashboard agrees for a day, but original lots, returns and tax calculations still depend on a broken history.
Durable correction
Repair the missing event
Add the omitted reinvestment, apply the corporate action, correct the transfer, or confirm the pence scale. Current balances then follow from the ledger.
Investment record keeping questions
Short answers to the questions that surface when records are missing, a broker changes, or tax time exposes a gap.
How long do I need to keep investment records?
Keep purchase, reinvestment and corporate-action records for as long as you own the asset, then for at least the tax authority's normal review period after disposal. In the US that is generally at least three years after the relevant return, and longer in some circumstances. In the UK, records for an on-time Self Assessment return not connected with self-employment normally need to be kept for at least 22 months after the end of the tax year. Capital gains records that support the calculation must be kept for at least a year after the Self Assessment deadline, and longer if the return was late or HMRC has started a check. Self-employed people must keep business records for at least five years after the 31 January submission deadline. See the IRS guidance and HMRC record rules.
How long does my broker keep my statements?
SEC Rule 17a-4 gives US broker-dealers record-retention periods that commonly run for three or six years depending on the record, with the first two years in an easily accessible place. That is not a promise that every document will remain in your online portal indefinitely. Your basis evidence has a practical expiry date unless you retain your own copies.
What happens if I can't prove my cost basis?
If you cannot substantiate cost basis, the IRS may accept a zero basis, which can make the entire sale proceeds appear taxable as a gain. Contemporaneous confirmations, statements and corporate-action records are the strongest defence. UK taxpayers must calculate allowable expenditure themselves, so missing records can also distort the Section 104 pool. Seek professional advice when evidence cannot be recovered.
Does my cost basis transfer when I move brokers?
US basis for covered securities generally transfers, but older non-covered holdings, average-cost fund lots and off-market details can arrive incomplete. In the UK, book cost shown by a platform is not a substitute for the taxpayer's own records. Export transaction history and statements before moving, then compare quantities, acquisition dates and lots after the transfer.
How do I reconstruct cost basis from old statements?
Rebuild purchases and disposals chronologically from contract notes, confirmations and statements. Apply reinvested dividends, splits, spin-offs and mergers in date order, preserve your source documents, and write down the method and assumptions used. Obtain professional tax help where the chain cannot be supported.
Why doesn't my portfolio tracker match my broker?
A feed may omit corporate actions, dividend reinvestments, foreign-exchange effects or off-market transfers. Compare one holding at a time, checking transaction history and quantity before market value. Correct the underlying event rather than forcing today's balance to match.
What investment records should I keep for taxes?
Keep trade confirmations, account statements, Forms 1099-B, 1099-DIV and 1099-INT in the US, or contract notes and consolidated tax certificates in the UK. Also retain dividend-reinvestment records, corporate-action notices, fees and foreign-exchange evidence, and fair-market-value documents for gifted or inherited assets.
Is a portfolio tracker the same as a trading journal?
No. An investment record establishes what happened, including dates, quantities, proceeds and cost for tax reporting. A trading journal records why a decision was made and is mainly a behaviour tool. They solve different problems.
How do I keep records across multiple brokerage accounts?
Keep one continuing transaction ledger across every broker while leaving the brokerage accounts themselves where they are. Import each account's history, preserve account labels and source documents, and add new transactions consistently. Combining the record does not require transferring the assets.
Keep the history you will need later
Build the ledger before a broker change makes it urgent
Import the records you already have, review every proposed addition, and keep future transactions in the same continuing history.
Read-only broker sync with 30+ brokers on paid plans · CSV import auto-detects 28 formats on every plan