Key takeaways
What this article covers, in order:
- The 47th time you categorize the same latte
- What a bank rule usually looks like
- Rules worth writing on day one
- Rules you should not write
- How to write a rule that doesn't misfire
- Splits: the advanced move
A bank rule is an instruction you give your accounting software: "when a transaction looks like this, categorize it like that." Good rules handle the repeat lines you'd otherwise click through every week, like the same coffee shop, the same software bill, or the same fuel station. Bad rules quietly miscategorize things for months. Keep rules narrow, name them clearly, and review them a few times a year.
The 47th time you categorize the same latte
Here's a scene plenty of solo consultants will recognize. Priya, an illustrative marketing consultant in Denver, meets clients at the same café near her co-working space. In a year that's dozens of charges between $6 and $18, all reading something like "SQ *BEAN THERE CAFE DENVER CO."
Every single one, she clicks the line, picks "Meals," and hits save. By her 47th, she's annoyed. By her 80th, she's started ignoring the review queue altogether, which is far worse than the clicking.
A bank rule ends that loop. One instruction, written once: if the description contains "BEAN THERE CAFE," categorize as Meals. Done.
What a bank rule usually looks like
Across most accounting tools, a rule has three parts.
1. Conditions (the "if"). What the transaction must look like. Common options:
- Description contains, starts with, or equals some text
- Amount is equal to, greater than, less than, or between values
- It's money in or money out
- It came from a specific bank account or card
2. Actions (the "then"). What happens when it matches:
- Assign a category
- Assign a payee or vendor
- Add a memo or tag
- Split by percentage or fixed amount across categories
3. Behavior. Does the rule just suggest, or does it apply automatically? Some tools let you choose whether matching transactions still wait for your review.
Even if your software handles categorization differently, like with AI suggestions instead of hand-built rules, it helps to think in this "if this, then that" shape. It's how you'd train a new bookkeeper, too.
Rules worth writing on day one
Start with the transactions that are boring, frequent and never ambiguous.
| Rule | Condition | Action | Why it's safe |
|---|---|---|---|
| Phone bill | Description contains carrier name, money out | Phone and internet | Same vendor, same purpose every month |
| Design software | Description contains software name | Software and subscriptions | Single use |
| Bank fee | Description contains "SERVICE FEE," from checking | Bank fees | Standard bank wording |
| Fuel | Description contains your usual gas station | Vehicle expenses | If the card is only used for business fuel |
| Card payment | Description contains "PAYMENT THANK YOU," on the credit card | Transfer from checking | Always a transfer, never income |
| Rent | Description contains landlord name, amount equals $1,200.00 | Rent | Amount condition prevents mistakes |
That card payment rule is quietly one of the most valuable. Misfiled card payments are a big source of inflated income.
Rules you should not write
Some transactions look repetitive but aren't. Automating them bakes a mistake into every month.
Big-box stores and online marketplaces. "AMAZON" or "COSTCO" could be supplies, inventory, equipment or personal. A rule that sends them all to Office supplies will be wrong regularly.
Peer-to-peer payments. "ZELLE TO J SMITH" might be a contractor in June 2026 and a refund to a customer in August 2026.
Deposits, as a group. A rule that calls every incoming deposit "Sales" will mislabel transfers from savings, loan proceeds, owner contributions and vendor refunds. If you want a rule for deposits, make it specific to one payer.
Anything that should be matched to an invoice or bill. If a $2,400 client payment pays invoice #1045, it should be matched to that invoice so your receivables drop. A rule that just categorizes it as income can leave the invoice looking unpaid.
Restaurants in general. Business meals and personal dinners hit the same merchants.
How to write a rule that doesn't misfire
A few habits separate good rules from troublesome ones.
- Use the most distinctive part of the description. "BEAN THERE CAFE" beats "CAFE," which will catch half the coffee shops in America.
- Add an amount condition for fixed bills. Rent of exactly $1,200 is rent. A $4,800 payment to the same landlord is something else and deserves a look.
- Limit by account. If only your business card pays for fuel, set the rule to apply only to that card.
- Keep money-in and money-out separate. A vendor refund looks like the vendor's charge in reverse.
- Prefer "suggest" over "auto-accept" for new rules. Watch how it behaves for a month, then trust it more.
- Name the rule plainly. "Phone bill: carrier, monthly" is easier to audit later than "Rule 14."
Splits: the advanced move
Some recurring charges are partly business and partly personal, and the split is stable. A cell phone used 70% for the business is the classic example. A rule can split the $90 bill into $63 Phone and internet and $27 Owner draw automatically.
Two cautions. First, the split percentage should reflect real use, and if you're unsure what's reasonable, ask your CPA once and write down the answer. Second, review split rules whenever your situation changes. Plenty of people set 70/30 in 2023 and never touch it again.
The quarterly rule check-up
Rules decay. Vendors rename themselves, your business changes, and the café you met clients at closes. Every three months, say in the first week of each new quarter, spend 15 minutes on this checklist:
- [ ] Delete rules for vendors you no longer use.
- [ ] Look at the transactions each major rule touched last quarter. Any obvious misfits?
- [ ] Check for two rules that could both match the same transaction, and decide which should win.
- [ ] Review split percentages.
- [ ] Look at your "Uncategorized" or review queue for new repeat vendors that deserve a rule.
- [ ] Confirm transfer rules still point at the right accounts, especially if you opened or closed one.
Rules vs AI suggestions
You'll often see both in modern accounting tools, and they work differently.
- Rules are explicit. They do exactly what you wrote, every time, including when what you wrote is wrong.
- AI suggestions are predictions based on patterns and past behavior. They adapt, but they can't promise the same answer every time.
In practice, explicit rules are great for a short list of rock-solid cases (rent, card payments, a single-purpose subscription). AI suggestions are useful for the broad middle. Your review covers the rest.
How HelloBooks helps
In HelloBooks, transactions come in through a live bank feed (connect most US banks and credit cards) or a CSV statement import and land in a review list where you set the category.
- AI auto-categorization on Starter ($14.99/month) and higher plans suggests categories based on the transaction, which takes care of a lot of the repetitive lines this post is about. You review and accept.
- The Free plan includes free AI credits to get started. If AI credits run out, AI categorization pauses and you categorize by hand; the books keep working.
- P&L, Balance Sheet and Cash Flow reports on every plan make it easy to spot a category that looks off.
See what else is included under bookkeeping features and automated bookkeeping. Freelancers may also like accounting for freelancers.
FAQs
What is a bank rule in accounting software?
It's a saved instruction that automatically categorizes transactions matching certain conditions, such as a description containing a vendor's name or an exact amount. It saves you from categorizing the same thing over and over.
Can a bank rule be wrong?
Yes. A rule does exactly what it's told. If the condition is too broad, like "description contains CAFE," it will catch transactions it shouldn't. Narrow conditions and periodic reviews keep rules accurate.
Should rules apply automatically or wait for review?
Start with review. Once a rule has behaved correctly for a month or two, letting it apply more automatically is reasonable for simple, fixed transactions.
Do I need rules if my software has AI categorization?
Not necessarily. AI suggestions cover a lot of the same ground. The "if this, then that" thinking is still useful for deciding what you can trust and what you should always check, like transfers and owner spending.
How many bank rules should a small business have?
There's no right number. A solo business might be fine with a dozen. What matters is that each one is specific, still relevant, and easy to understand when you read its name.
Write the rule once, check it every few months, and get your Monday mornings back.
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