FinCEN Currency Transaction Reports (CTRs)

You deposited $11,000 in cash. The bank filed a Currency Transaction Report (CTR). The IRS has a copy. They want to know the source of the cash.

FinCEN 31 CFR 1010.311 governs Currency Transaction Reports (CTRs). Banks must file a CTR for any cash transaction (deposit, withdrawal, exchange) over $10,000. This page covers the 5 key provisions, the documentation requirements, and the recon cutoff tool’s per-CTR-handling.

FinCEN 31 CFR 1010.311 requires banks to file a Currency Transaction Report (FinCEN Form 104) for any cash transaction over $10,000. Multiple transactions that aggregate to over $10,000 in a single day also trigger a CTR (“structuring” is illegal and triggers separate SAR). The CTR is filed electronically with FinCEN within 15 days.

The recon cutoff tool’s per-CTR-flag identifies cash transactions over $10,000. The recon cutoff tool’s per-structuring-flag identifies multiple smaller transactions that aggregate over $10,000. The recon cutoff tool’s per-15-day-deadline tracks the filing deadline.

For the broader bookkeeper workflow, see the bookkeeper workflow. For the audit archive, see the 5-year audit archive. For the IRS Pub 552, see the IRS Pub 552.

What Is FinCEN 31 CFR 1010.311?

FinCEN (Financial Crimes Enforcement Network) is a bureau of the US Treasury. 31 CFR 1010.311 is the section of the Bank Secrecy Act (BSA) regulations that requires banks to file Currency Transaction Reports. The recon cutoff tool’s per-FinCEN-tracking handles the regulation updates. The current version is 2026.

What most guides miss about this workflow is that the quality depends on the mechanism, not on the tool. Two tools that look different on the surface often run the same 4-step process underneath: read, find, parse, verify. The difference is in how well each step handles edge cases (merged cells, missing balances, non-standard date formats, scanned vs digital input).

Choosing between tools based on UI alone misses the actual quality lever.

The regulation is the authoritative source for CTR filing in the US. The recon cutoff tool’s per-FinCEN-citation-flag tracks the citations. The recon cutoff tool’s per-FinCEN-effective-date tracks the effective date of each provision.

5 Key Provisions of 31 CFR 1010.311

5 provisions cover the CTR requirements. The recon cutoff tool’s per-provision-handling covers all 5.

Provision 1: The $10,000 Threshold

Any cash transaction (deposit, withdrawal, exchange) over $10,000 triggers a CTR. The recon cutoff tool’s per-10k-flag identifies transactions over $10,000. The recon cutoff tool’s per-CTR-trigger-handling generates the CTR trigger.

Provision 2: The Aggregation Rule

Multiple cash transactions that aggregate to over $10,000 in a single day also trigger a CTR. The recon cutoff tool’s per-aggregation-flag identifies aggregating transactions. The recon cutoff tool’s per-structuring-warning handles the structuring case.

Provision 3: The 15-Day Filing Deadline

The CTR must be filed within 15 days of the transaction. The recon cutoff tool’s per-15-day-flag tracks the deadline. The recon cutoff tool’s per-CTR-filing handles the filing.

Provision 4: The Form 104 Requirement

The CTR is filed on FinCEN Form 104. The form includes the transaction details, the customer information, and the bank information. The recon cutoff tool’s per-form-104-handling generates the form data.

Provision 5: The 5-Year Retention

Banks must retain CTR documentation for 5 years. The recon cutoff tool’s per-5-year-flag tracks the retention period. The recon cutoff tool’s per-CTR-archive stores the 5-year set.

How 31 CFR 1010.311 Affects Bank Statement Users

5 practical impacts. The recon cutoff tool’s per-user-impact-flag tracks each impact.

Impact 1: CTR awareness. Any cash transaction over $10,000 triggers a CTR. The recon cutoff tool’s per-CTR-awareness-flag warns the user.

Impact 2: Structuring avoidance. Multiple smaller transactions to avoid CTR trigger is illegal (“structuring”). The recon cutoff tool’s per-structuring-warning handles the warning.

Impact 3: Source of cash documentation. The bank may ask for the source of cash. The recon cutoff tool’s per-cash-source-flag identifies the documentation needed.

Compliance Documentation Checklist

5 documentation items. The recon cutoff tool’s per-FinCEN-checklist generates the per-transaction checklist.

Item 1: Source of cash documentation. The recon cutoff tool’s per-cash-source-archive stores the documentation.

Item 2: CTR copy from the bank. The recon cutoff tool’s per-CTR-archive stores the CTR.

Item 3: 5-year retention of CTR records. The recon cutoff tool’s per-5-year-archive stores the 5-year set.

Item 4: Aggregate transaction log. The recon cutoff tool’s per-aggregate-log tracks the daily aggregate.

Item 5: Suspicious activity report (SAR) if applicable. The recon cutoff tool’s per-SAR-flag identifies the SAR case.

Common Mistakes with 31 CFR 1010.311

3 common mistakes. The recon cutoff tool’s per-FinCEN-mistake-flag identifies each.

Mistake 1: Structuring to avoid CTR. A common failure mode is the customer making multiple smaller deposits to avoid the $10,000 threshold. This is illegal and triggers a SAR. The recon cutoff tool’s per-structuring-warning handles the warning.

Mistake 2: Not documenting the source of cash. A common failure mode bookkeepers report is the customer not documenting the source. The recon cutoff tool’s per-source-flag handles the documentation.

Mistake 3: Missing the 15-day filing deadline. The recon cutoff tool’s per-15-day-deadline tracks the deadline.

How 31 CFR 1010.311 Connects to Our Cluster

3 cluster spokes cite 31 CFR 1010.311. The recon cutoff tool’s per-citation-flag tracks the citations.

5-year audit archive cites 31 CFR 1010.311 for the retention period. Bookkeeper workflow cites 31 CFR 1010.311 for the cash handling. Multi-entity reconciliation cites 31 CFR 1010.311 for the aggregate transaction case.

Related Regulations and Resources

5 related resources.

Fannie Mae Selling Guide B2-1.5-02 . HUD 4000.1 II.A.4 . IRS Pub 552 . ECOA Reg B . Bank statements and federal regulations . The bank statement converter handles all the steps with the integrity check at the end. The bank statement converter handles all the steps with the integrity check at the end.

The bank statement converter handles all the steps with the integrity check at the end. The bank statement converter handles all the steps with the integrity check at the end.

Related:

This topic is part of the US bank-statement federal-regulations cluster on this site. The consolidated hub covering Reg E, Reg CC, Reg DD, ECOA Reg B, BSA, FinCEN CTR/SAR, FHA bank-statement guidelines, and Fannie Mae and Freddie Mac requirements now lives in the complete federal regulations bank statement guide.

For related reading on the broader clusters, the
covers credit-card-side mechanics, the
covers bank-account-side mechanics, and the expanded bank statement anatomy is a useful primer.

More on the broader cluster

For the broader context on US bank-statement reading, see the consolidated hubs on merchant category codes, payment rails, and the statement anatomy. These hubs work together to cover credit-card statements, bank-account statements, and the categorization signals that survive merchant-name truncation.

When reconciliation runs into edge cases, the practical answer usually lives in the federal-regulations cluster, the bookkeeper-resource cluster, or the credit-card-statements cluster. Each offers a domain-specific take on the same underlying signal.

Easy Statement Sheet reads bank-statement and credit-card statement PDFs into a clean four-column output (Date, Description, Amount, plus Merchant Category Code for credit-card statements, plus the running balance for bank-account statements). Files are never stored.

The first three statement conversions are free, no card required. Plans start at $15 per month. The four-column output preserves the categorization signals without retyping, so the rule-based reconciliation layer survives merchant-processor changes.

Decision framework for this topic

For the broader context on US bank-statement reading, see the consolidated hubs on merchant category codes, payment rails, and the statement anatomy. These hubs work together to cover credit-card statements, bank-account statements, and the categorization signals that survive merchant-name truncation.

Each hub is built to be the canonical reading for one cluster of search intent, with cross-cluster links that take you to the right next node.

When reconciliation runs into edge cases, the practical answer usually lives in the federal-regulations cluster, the bookkeeper-resource cluster, or the credit-card-statements cluster. Each offers a domain-specific take on the same underlying signal. The merchant category code is the same whether the reader is the small-business owner, the bookkeeper, or the lender.

For lender workflows, the merchant category code on credit-card statements and the ACH SEC code on bank-account statements are the two signals underwriters most often scan first. Lenders use the four-column conversion output as a quick reference for what the borrower actually spent.

Cash advances flagged at MCC 6011 and quasi-cash at MCC 6051 draw particular scrutiny at mortgage underwrite, and crypto exchanges on the ACH rail draw additional questions for self-employed applicants.

For bookkeeper workflows, the categorical signal ties directly into the chart-of-accounts. A bookkeeper who maintains categorization rules keyed off the merchant category code can process dozens of clients per week without manual categorization of common merchant types. The conversion output is the durable input; the rule set is the durable work product.

Easy Statement Sheet reads bank-statement and credit-card statement PDFs into a clean four-column output (Date, Description, Amount, plus Merchant Category Code for credit-card statements, plus the running balance for bank-account statements). Files are never stored. The conversion runs entirely in memory and produces a deterministic output that downstream tools can parse.

The first three statement conversions are free, no card required. Plans start at $15 per month. The four-column output preserves the categorization signals without retyping, so the rule-based reconciliation layer survives merchant-processor changes. For bookkeepers handling dozens of clients per month, this is the highest-leverage workflow to standardize.

Related reading and broader clusters

For the broader context on US bank-statement reading, see the consolidated hubs on merchant category codes, payment rails, and the statement anatomy. These hubs work together to cover credit-card statements, bank-account statements, and the categorization signals that survive merchant-name truncation.

Each hub is built to be the canonical reading for one cluster of search intent, with cross-cluster links that take you to the right next node.

When reconciliation runs into edge cases, the practical answer usually lives in the federal-regulations cluster, the bookkeeper-resource cluster, or the credit-card-statements cluster. Each offers a domain-specific take on the same underlying signal. The merchant category code is the same whether the reader is the small-business owner, the bookkeeper, or the lender.

For lender workflows, the merchant category code on credit-card statements and the ACH SEC code on bank-account statements are the two signals underwriters most often scan first. Lenders use the four-column conversion output as a quick reference for what the borrower actually spent.

Cash advances flagged at MCC 6011 and quasi-cash at MCC 6051 draw particular scrutiny at mortgage underwrite, and crypto exchanges on the ACH rail draw additional questions for self-employed applicants.

For bookkeeper workflows, the categorical signal ties directly into the chart-of-accounts. A bookkeeper who maintains categorization rules keyed off the merchant category code can process dozens of clients per week without manual categorization of common merchant types. The conversion output is the durable input; the rule set is the durable work product.

Easy Statement Sheet reads bank-statement and credit-card statement PDFs into a clean four-column output (Date, Description, Amount, plus Merchant Category Code for credit-card statements, plus the running balance for bank-account statements). Files are never stored. The conversion runs entirely in memory and produces a deterministic output that downstream tools can parse.

The first three statement conversions are free, no card required. Plans start at $15 per month. The four-column output preserves the categorization signals without retyping, so the rule-based reconciliation layer survives merchant-processor changes. For bookkeepers handling dozens of clients per month, this is the highest-leverage workflow to standardize.