MosoFin · Balance sheet reconciliations, in plain words

Does each number on my balance sheet have real proof behind it?

Your balance sheet shows one number for each account. Behind most of those numbers, there must be a detailed list that adds up to the same amount. This skill compares each balance with its list, and it tells you which accounts have proof and which do not.

The 20-second version

You name the company, the accounts and the date. For each account, the skill compares the balance in your books with the support for it. It explains each difference, puts an age on it, and suggests corrections. An account without independent support stays "not reconciled". It never changes your books.

What a run finds

Seven accounts at Northbrook Trading on 30 September

Northbrook Trading works in US dollars and keeps its books on the accrual basis. The owner names seven accounts for this run. The date is Wednesday 30 September 2026. For each account, the skill reads two sides. The first side is the balance in the books. Accountants call it the GL balance (general ledger). The second side is the support: a detailed list, a schedule or a document from outside the books.

An accounting textbook gives the basic rule. The total of the customer accounts in the detail must equal the receivables account in the books. If the two totals do not agree, there is a mistake¹.

Account	Books $	Support	Support $	Difference $	Result
Payroll clearing	4,023.40	Must be zero	0.00	4,023.40	Investigating. Five open lines
Accounts receivable	68,950.00	Customer aging, in the same books	68,200.00	750.00	Investigating. Owner and date set
Accounts payable	58,400.00	Supplier aging, in the same books, and payments after the date	58,400.00	0.00	Reconciled
Prepaid expenses	22,100.00	Prepaid schedule, uploaded	14,850.00	7,250.00	Reconciled, with 3 proposed entries
Accrued expenses	27,790.00	Accrual schedules	25,750.00	2,040.00	Reconciled, with 1 proposed entry
Fixed assets, net	126,050.00	Asset register, not supplied	—	—	Not reconciled (support not supplied)
Term loan	300,000.00	Loan schedule, uploaded	300,000.00	0.00	Reconciled
In scope	607,313.40

Example figures for a made-up company, in dollars. The seven named accounts are the example's choice. The skill also accepts "all balance sheet accounts". The bank account goes to the bank reconciliation skill.

Two results need a note. For prepaid expenses and accrued expenses, the skill explains every difference and proposes corrections. "Reconciled" here means "reconciled when a person posts the proposed entries". The books do not agree with the support yet. The skill's status list does not name this case, so this is our reading of it.

Reconciled4Payables, prepaid, accrued and the loan

Investigating2Payroll clearing and receivables

Not reconciled1Fixed assets: the register is missing

Evidenced79.2%607,313.40 − 126,050 = 481,263.40, and 481,263.40 ÷ 607,313.40 = 79.2%

The skill asks how much of the balance sheet has evidence on its support side. It gives no formula for that figure. This page divides the evidenced balances by all the balances in scope.

The mistake it catches

A total that agrees with itself is not proof

The skill exists to stop one mistake: a tie-out that never happened. One version is an account with no support at all. The other version is "support" that comes from the same books. Both can look complete.

What the skill does

Receivables at Northbrook, with a two-sided result

Customer aging against itselfsame system

Books 68,950 − aging 68,200$750

Customer payments 1 to 9 October$31,400

The aging comes from the same books, so its tie is only a mechanical check. The skill tests it against the payments that came in after the date. The $750 stays open, with an owner and a date.

The common shortcut

Print the aging and call the account reconciled

Aging total68,200

Independent testnone

Fixed assets"tied" with no register

The file looks complete, but nothing outside the books supports it. A missing register gives no proof for $126,050 of fixed assets.

A federal guide on internal control lists "reconciliations of summary information to supporting detail" as a common control². That guide is a US government standard from 2001, and a revised version came in 2025. We use it only for the idea: a reconciliation is a control. A control on made-up data, or with no support, gives you no protection. So the skill never signs off a reconciliation on test data, and it never calls an unsupported account reconciled.

What it explains

Every difference gets a type, an owner and an age

The skill puts each difference in one of three types. A timing item clears by itself next period, for example a payment in transit. The skill records it and does not adjust it. A permanent item is an error, and the skill proposes an entry for it. An investigating item has no explanation yet. That is normal, if a person owns it and has a target date.

Prepaid expenses: $7,250

Three permanent items

September costs not booked: 600 + 400 + 150 = 1,150. August costs not booked: 550 + 400 + 150 = 1,100. A refundable landlord deposit of 5,000 that belongs in a different asset account. 1,150 + 1,100 + 5,000 = 7,250. The skill proposes the move of the deposit as an entry.

Accrued expenses: $2,040

One permanent item

The books show 27,790. The schedules show 14,650 + 2,100 + 9,000 = 25,750. The difference, 27,790 − 25,750 = 2,040, is an August electricity accrual that nobody reversed in September. The proposal reverses it.

Payroll clearing: $4,023.40

Five open lines

This account must be zero, so the skill does it first. Lines: 23.40, 640, 1,150, 410 and 1,800, which add up to 4,023.40. Each line goes to the payroll lead, with a target date of Friday 16 October 2026.

The August items, 1,100 and 2,040, come from a closed month. The skill proposes the entries. The opening check finds no change to a closed period, so the skill's rule for possible prior-period adjustments does not apply here. You and your accountant decide how to treat the August amounts.

The skill then ranks the items by size and by age. You set the size limit. At Northbrook it is $500 for each account. Items above it need immediate action: three clearing lines (640, 1,150 and 1,800), the $750 in receivables, the three prepaid items and the 2,040 accrual. Items older than three months must go to a manager, whatever their size. In payroll clearing, that is 23.40 (more than a year old), 640 and 1,150. The 410 is 92 days old, at the three-month limit.

The US securities regulator's staff says that a percentage limit is acceptable as a first test only. A small item can still matter³. The skill asks for your limit and does not choose one. The skill adds its own rule: a small item that stays open for a year usually means that nobody owns the account.

Proposed entries41,150 + 1,100 + 5,000 + 2,040 = 9,290

Accounts over $5004Clearing, receivables, prepaid, accrued

Lines over 3 months323.40, 640 and 1,150, all in payroll clearing

What it refuses

"Put the $750 in suspense so it ties"

The owner asks the skill to move the $750 to a suspense account. The skill says no, one time, and gives the reasons. It never forces a difference to agree. Accountants call that a plug. It never writes to your books. The $750 is more than Northbrook's $100 limit for small write-offs. Also, a write-off never goes to a suspense account on the balance sheet. That only moves the difference to another account, which must also reconcile.

Instead, the $750 stays open. It is probably a journal entry that someone posted to receivables without a customer. The bookkeeper owns it, with a target date of Friday 9 October 2026. The skill also lists the checks that found nothing: no late entries for September, no foreign currency and no rounding difference.

How a run starts

Eight questions, in one message

The skill asks these first, in one short batch. It asks only for what it cannot already see.

Use MosoFin for this run, or upload the data yourself?
MosoFin is the connection to your books and the other platforms you link. With it, the skill reads from there. Without it, you upload files, and the checks are the same. If your account has no MosoFin tools, the skill says once that the run is manual.
Which company? For a group, which entities?
The skill reconciles each company by itself. On the MosoFin path, it lists your connected companies by name and asks. It never chooses one for you.
Which accounts: named accounts, or all balance sheet accounts?
The answer sets the sheets of the workpaper and the support for each account. This answer is necessary.
Which period? What is the period-end date?
The date sets every balance and every cut-off. The skill never chooses a default date.
For each account with support outside the books, where is the schedule, and can you supply it?
Examples are prepaid, fixed asset, lease, payroll, loan and tax schedules, and bank statements. Without the schedule, the account stays "not reconciled", with the gap and an owner named.
What size of difference is too large?
Accountants call this the materiality threshold. The skill suggests a basis and asks. It never assumes a limit.
Do you have last period's reconciliation?
The skill needs it to check the items that stayed open from last period. Without it, the skill says that it could not do this check.
Who prepares, and who reviews?
The workpaper names both. They should not be the same person.

On the MosoFin path, the skill also asks for your approved limit for small write-offs, and the profit and loss account that receives them. At Northbrook, the limit is $100. Then the skill reads the plan back and waits for your yes. Its own example says "all balance sheet accounts". This page uses seven named accounts.

"Reconciling all balance sheet accounts of Northbrook Trading at 30 September, with the GL read from your Mosofin connection. ... the fixed asset register is still outstanding, so fixed assets will show as not reconciled. Materiality $500; prepared by the bookkeeper, reviewed by the controller. Shall I go ahead?"

What you need

Connect your books, then supply the outside schedules

Connected with MosoFin

It reads the books side, and asks for the rest

It reads back the workspace and the company by name, and waits for your yes
It reads the trial balance, the balance sheet, the chart of accounts and the detail behind each balance
It reads the support for receivables, payables and clearing accounts, because that detail is in the same books
You still supply the support from outside the books: prepaid, fixed asset, lease and loan schedules, tax filings and bank statements

Uploading instead

One checklist

Trial balance at the period end, CSV or XLSX, necessary
Support for each account: agings, schedules, filings or statements, CSV, XLSX or PDF, necessary for each account
Chart of accounts, CSV or XLSX, necessary for the proposed entries
Accounts, period end, company name and currency, typed in the chat, necessary
Detail of the books for the accounts, and last period's reconciliation, recommended
Size limit, preparer and reviewer, typed in the chat, recommended

What you get back

One sheet for each account, and a coverage sheet

The two sidesThe balance in the books and the support, each with its source and date, and the difference.

Each difference explainedIts type, amount, age, owner and target date. The checks that found nothing are on the sheet too.

Proposed entriesCorrections in your real account names, for a person to post. At Northbrook, four entries for 9,290.

CoverageFor each account, how the skill got each side, and what nobody could prove, with an owner.

Each account sheet also has a roll-forward where the account has a lot of activity. The skill leaves the review dates blank for the preparer and the reviewer. The skill asks whether you want an Excel file first. At Northbrook, the name is "BS_Recs_2026-09_Northbrook Trading.xlsx". After you see the results, it offers to save your settings for the next run. These are the source for each account, the $500 limit and the three-month rule. They also include the people, the write-off limit and the accounts that must be zero. It never saves balances or the workpaper.

What it never does

Six rules that never bend

Never reads MosoFin without asking. A connected account is not permission to read it.
Never reads anything before you answer the intake questions and say yes to the read-back.
Never writes, updates or deletes anything, in any system. Every entry that it makes is a proposal for a person to post.
Never calls an account reconciled without independent support. Missing support means "not reconciled". The skill never reconciles an account to another view of itself.
Never forces a difference to agree, and never adjusts a timing difference. It records timing items and watches them. Every open item has an owner and a target date.
Never chooses the period, the size limit or the company for you. It never signs off a reconciliation on test data.

Words you'll hear

Six terms, in plain English

Reconciliation: A check that the balance in the books agrees with the detail that supports it¹.
Support: The list, schedule or document that must add up to the balance, for example a loan schedule.
Reconciling item: One explained part of a difference. The skill uses three types: timing, permanent and investigating.
Plug: An amount that someone adds only to make two totals agree, with no explanation.
Clearing account: A waiting room for money on its way somewhere else. Its balance must come back to zero.
Materiality: The size of a difference that is too large to leave. Size is not the only test³.

Sources

Where the facts on this page come from

The sources are an accounting textbook, a US government guide and a statement from the staff of the US securities regulator. We found each one on 28 October 2026 in search results. We did not open the pages, so follow each link for today's wording. What the skill does comes from the skill's own files.

OpenStax: Principles of Accounting, Volume 1, 7.2 Describe and Explain the Purpose of Special Journals and Their Importance to StakeholdersThe total of the customer accounts in the receivables detail must equal the receivables control account. If they do not agree, there is a mistake. The textbook describes a manual detail ledger.
GAO: Internal Control Standards (Green Book guidance, GAO-01-1008G)Lists "reconciliations of summary information to supporting detail" among common control activities. A US government guide from 2001. The Green Book had a revision in 2025.
SEC: Staff Accounting Bulletin No. 99, MaterialityA percentage limit is acceptable as a first assessment, but the use of a limit alone has no basis in law or accounting literature. Staff guidance, not a Commission rule.

No outside authority backs the three item types, the three-month rule, the $500 limit, the $100 write-off limit, the status list or the coverage sheet. They are the skill's own rules, or choices for this example. We made up Northbrook Trading and every figure in the example. All three sources are US sources.

About this skill

This page explains balance-sheet-reconciliations, from the MosoFin finance skills library, MosoFin/mosofin-finance-skills on GitHub. Read the skill on GitHub → The skill is in the card format on the main branch. It merged in PR #1 on 26 October 2026, and a bookkeeping-audit correction followed on 27 October 2026. This page describes that version. Want the worked examples? Learn it step by step →