How to Combine Portfolios From Multiple Brokers Without Connecting Your Accounts

1. A portfolio is a ledger, not a balance

Suppose three accounts are worth $60,900 in total today. That number alone cannot tell you whether the investments performed well.

An illustrative history might look like this:

Someone else could have the same $60,900 balance after contributing $70,000. The current value is identical; the outcome is not.

Transfers make the picture even easier to distort. If I move $20,000 of securities from Broker A to Broker B, Broker A records assets leaving and Broker B records assets arriving. At the account level, those are real events. At the combined-portfolio level, I have contributed nothing new. Treating the receiving side as a fresh investment would inflate my lifetime contributions by $20,000.

The same problem appears with dividends, commissions, withholding, currency conversion and partial sales. A useful combined portfolio must preserve the events that produced the balance, not only the balance itself.

2. Four ways to put the accounts together

There is no universally best method. The right one depends on how many accounts you have, how often you trade, how much history you need and what kind of access you are comfortable granting.

1. Let one broker aggregate the others

Some brokers provide their own aggregation tools. This can be convenient because the analysis lives in an institution you already use.

The obvious limitation is coverage. The broker must support the other institution or account type, and the resulting view may be designed around current allocation rather than the complete transaction history you want to preserve. Employer share plans, older regional brokers and manually held investments are often the accounts that make consolidation necessary in the first place.

2. Use a tracker with live account connections

Connected trackers offer the least manual work. Once authorized, they can refresh holdings and transactions without another export.

It is important not to collapse every connection into "giving an app your brokerage password." A modern OAuth flow redirects you to the financial institution, where you authenticate and authorize access. The third-party application receives permissioned access rather than your password. Plaid's OAuth documentation describes exactly this model.

That is a meaningful security improvement over credential sharing. It does not remove every trade-off.

A connected service still needs continuing permission to retrieve financial data. Its usefulness depends on support for your institution, the fields supplied by that institution and the depth of history available through the feed. For example, Plaid Investments documents up to 24 months of investment transactions, while its standard account endpoint uses cached balances that typically update about once a day when the connection is healthy. Other providers have different limits; the point is that "connected" does not automatically mean complete or real-time.

For an active investor who wants automatic daily updates, this can still be the right compromise. For somebody who checks a long-term portfolio once a month, permanent access may solve a problem they do not actually have.

3. Maintain a spreadsheet

A spreadsheet is transparent, flexible and independent of any provider. For a small portfolio, it may be all you need.

The workload grows with every exception. You have to standardize tickers, preserve dates, account for commissions, convert currencies, distinguish dividends from deposits, match transfers and prevent the same transaction from being pasted twice. Then you have to maintain the formulas.

The spreadsheet does not usually fail in a dramatic way. It becomes less trustworthy gradually. One missing dividend, one overwritten formula or one transfer recorded as a contribution can produce a plausible result that is still wrong.

4. Import statements periodically

The fourth option is to treat each broker statement as a source document and build the combined ledger from those documents.

This is less automatic than a live connection, but it is not an improvised workaround. Broker reports can contain a surprisingly complete record. Interactive Brokers says its Activity Statements include positions, cash balances, fees, corporate actions, interest, dividends and trades. Its reporting tools also allow investors to create configurable CSV, XML and text exports through Flex Queries. IBKR documents the available reporting fields here.

DEGIRO similarly provides separate account, transaction and portfolio reports, with exports available in Excel, PDF and CSV formats. Its reporting documentation makes an important distinction: a portfolio overview is a snapshot of open positions, while account and transaction statements contain the activity behind those positions.

That distinction matters. A holdings screenshot can tell a tracker what you own today. It usually cannot reconstruct when you bought it, what you paid, what income it produced or how much of the current value came from your own contributions.

3. What the combined record actually needs

If I were evaluating any multi-broker tracker, I would look for more than a clean dashboard. I would want to know whether it preserves the following:

• The source account. Every transaction should retain its origin. Combining accounts should not erase the ability to trace a number back to a broker statement.
• Stable instrument identification. A ticker alone is not always enough. The same security can trade in different currencies or on different exchanges, and the same short ticker can refer to different instruments. ISINs and market identifiers help disambiguate them.
• Dated external cash flows. Contributions and withdrawals need dates and amounts. Without them, money-weighted return is guesswork.
• Internal transfers. Moving cash or securities between my own accounts should not become a new contribution to the combined portfolio.
• Income and costs. Dividends, interest, commissions and withholding should remain separate. Folding everything into an unexplained gain hides exactly the leakage many investors are trying to understand.
• Historical currency conversion. A contribution made in euros should retain its value at the exchange rate on the transaction date. Re-converting the old contribution at today's rate silently rewrites history.
• Duplicate detection. Overlapping statements are normal. I may export January through August in September and January through September in October. A safe importer should recognize previously recorded transactions before it changes the portfolio.
• A review step. PDF layouts vary, CSV columns differ and corporate actions can be ambiguous. Extraction should be treated as a draft to verify, not as unquestionable truth.

4. The reconciliation test

After consolidation, the portfolio should pass a basic accounting identity:

For example:

If the two sides do not match, something is missing, duplicated or classified incorrectly. That disagreement is useful information. A tracker that simply assigns every unexplained difference to "market return" will always balance, but it cannot tell you whether the result is correct.

Performance requires another distinction. The return percentages shown by three brokers cannot simply be averaged. Contributions occurred at different times and in different amounts. Time-weighted return attempts to remove the effect of external cash flows so the underlying portfolio can be compared across periods; money-weighted return reflects the investor's actual timing and size of those flows. Even professional performance standards require explicit policies for external cash flows and generally use time-weighted returns for comparability. The CFA Institute's overview of the GIPS standards explains why this treatment matters.

For a personal portfolio, both views are useful. They answer different questions:

• What did the portfolio do? Time-weighted return.
• What happened to my money? Money-weighted return, often calculated as XIRR.

Neither is trustworthy without a sufficiently complete ledger.

5. "No broker connection" does not mean "no privacy decision"

A statement-based workflow removes one kind of access: the tracker has no standing authorization to query the broker, and it cannot use a broker connection to place trades or move money.

But a statement is still a sensitive financial document. It may contain a name, address, account number, holdings and transaction history. Uploading it requires a different set of questions:

• Is the original file stored, and for how long?
• Is the document sent to another processor for extraction?
• Which fields are retained after parsing?
• Can I review the extracted data before saving it?
• Can I delete the portfolio and account myself?
• Does the provider have an independent security certification or penetration test?

The right comparison is not "connected equals dangerous, document equals safe." The right comparison is the exact access, retention, processing and deletion model of each service.

OAuth can be a sensible choice when it is implemented well and the institution supports it. Statement import can be a sensible choice when you want broad compatibility and periodic control. Manual entry remains the lowest-data-sharing option, at the cost of the most work.

6. The approach I ended up building

I ran into this problem while trying to maintain one coherent history across accounts. I wanted the combined analysis, but I did not need another service continuously connected to my brokerage accounts. That is why I ended up building BorderFolio around a document-in workflow.

Each broker or account can remain a separate portfolio, while the combined view brings them together. BorderFolio accepts PDF and CSV statements, as well as screenshots or photos when no useful export exists. It extracts positions and transactions, shows the result for review and skips transactions it has already imported. It never asks for broker credentials.

There is a trade-off, and it should be stated plainly. Arbitrary statement layouts are extracted using the OpenAI API, so the contents of an uploaded document are sent to that processor. BorderFolio keeps the original file in private storage only so a failed import can be retried and deletes it automatically within seven days. The product is still young: it does not have SOC 2 or ISO 27001 certification or a third-party penetration test. Manual entry is available for anyone who does not want to upload a statement. The complete details are published on the security and data-handling page.

I do not think this approach replaces connected trackers. If you trade frequently and want intraday updates, a reliable API connection is probably more convenient. If you need jurisdiction-specific tax filing, a portfolio tracker is not a substitute for tax software or an accountant. And if you have one account with five holdings, a spreadsheet may remain perfectly adequate.

Statement import is most useful for the awkward middle: several brokers, long holding periods, regular contributions and enough history that starting from today would throw away the part you actually want to understand.

The dashboard is the last step

Combining portfolios is often presented as a visualization problem. Put every account on one screen, draw an allocation chart and show a total balance.

The dashboard is the easy part.

The real product is the ledger underneath it: where every position came from, when money entered, what moved internally, which income was paid, which costs were taken and whether the pieces add up.

The best multi-broker setup is not necessarily the one with the most automation. It is the one whose history you can explain.