How to Set Up Bookkeeping for Your SaaS as a Solo Founder

Most solo founders do their books the same way. Nothing for eleven months, then one bad weekend in front of a year of Stripe payouts, card statements and a folder called "receipts maybe". You guess at half of it, your accountant sends questions you cannot answer, and you still do not know if the business made money. This post is a lighter way: one bank account, one card, a short category list, and a 30 minute monthly close. It is written for a SaaS with a handful to a few hundred customers and no finance person. It is not tax advice. Rules differ by country, so use this to get organised and let a local accountant handle the filing.

Quick answer

Open a separate business bank account and one business card, and route every SaaS charge and every payout through them. Pick a simple tool (a spreadsheet works under about 50 transactions a month, accounting software after that). Use 10 to 15 categories, not 60. Record Stripe revenue gross, with fees as their own expense, so payouts reconcile. Save every receipt the day it arrives in one inbox or folder with a naming rule. Do a 30 minute close once a month: reconcile the bank, match receipts, check one number (cash in minus cash out), and note anything odd. If you sell annual plans, keep a small note of how much of that cash is still owed in service. Hand the year to an accountant in January with almost no questions left.

Why bookkeeping matters before you have real revenue

It is tempting to skip this until revenue is "worth it". Three things go wrong when you do:

• You cannot see your real margin. Hosting, email, AI API calls, domains and a dozen $9 tools add up. Without books, you price and plan on a feeling.

• Tax time gets expensive. Accountants bill for cleanup. Messy books turn a short job into a long one, and missing receipts can mean you lose deductions you were allowed to take.

• Selling, raising or even applying for a loan needs records. Any of those will ask for clean monthly numbers. Rebuilding two years of history later is miserable.

The fix is not a finance degree. It is a few boring habits set up once.

Step 1: Separate business money from personal money

This is the single most useful step. Open a business current account (many banks and fintechs offer free ones for sole traders and small companies) and get one business debit or credit card on it.

• Point your Stripe, Paddle or Lemon Squeezy payouts at the business account.

• Move every SaaS subscription, domain and API bill to the business card. Make a list first so you do not miss the annual ones.

• When you need money for yourself, transfer it out as one clear transfer (owner draw or salary, depending on your structure). Do not pay for groceries from the business card.

If a business charge does land on your personal card, do not panic. Log it as an expense paid personally, keep the receipt, and reimburse yourself with one transfer at month end. The goal is that every line on the business statement is a business line.

Step 2: Pick the smallest tool that works

You do not need the tool your friend's Series A company uses. Pick by volume.

Ask your accountant which tool they already use before you choose. Sharing access to the same software saves real money at year end.

If you go with a spreadsheet, these columns are enough: date, description, vendor or customer, category, amount in, amount out, currency, receipt link, notes. One tab per year, one row per bank line.

Step 3: Use a short category list

Too many categories is the most common way founders make this hard. You will hesitate on every line and then stop doing it. Start with something like this and only add a category when one bucket is clearly hiding something you want to watch.

Splitting hosting from third-party APIs is worth it for a SaaS. AI and email costs grow with usage, while hosting usually grows in steps. Seeing them separately tells you whether a new customer costs you more than you think.

If you want ideas for trimming that tools and hosting line, the SideHunt guide on keeping your side project's monthly bills under $20 walks through the usual suspects.

Step 4: Record payment processor revenue the right way

This is where SaaS books usually break. Stripe does not send you what your customers paid. It sends a payout: customer payments, minus fees, minus refunds, sometimes grouped across several days. If you log the payout as "revenue", your revenue is understated, your fees vanish, and nothing matches.

Record it in three parts instead:

1. Gross revenue for the period (what customers were charged).

2. Fees as an expense under payment processing fees.

3. Refunds and disputes as their own lines.

Gross minus fees minus refunds should equal the payouts that hit your bank. Stripe has a balance report that breaks down activity this way, and its payouts documentation explains how and when money moves to your bank. Download the monthly summary as CSV and keep it with your receipts. Most accounting tools also have a Stripe connector that does this split for you, which is one of the best reasons to upgrade from a spreadsheet.

A quick made-up example. Say "Notely", a $19 a month note app, charged customers $1,140 in March. Fees were $49.20, and one customer got a $19 refund. The bank received $1,071.80 in payouts. Your books show revenue $1,140, fees $49.20, refunds $19. The bank line of $1,071.80 matches. If instead you logged $1,071.80 as revenue, you would think your fees were zero and your pricing math would be off every month.

Multiple currencies? Record each payout in the currency your bank received it in, and keep the original currency in the notes column. Let your accountant or software handle conversion rules.

Step 5: Make receipts boring

Missing receipts are the main source of year-end pain. The fix is to never let them pile up.

• One receipts inbox. Create an address like receipts@yourdomain or a filter in your main inbox. Change the billing email on every tool to it.

• One folder, one naming rule. For example 2026-10-03_vercel_20.00usd.pdf. Date first so files sort themselves.

• Forward or upload the same day. Most accounting tools give you an email address that attaches receipts to transactions automatically.

• Photograph paper receipts at the till. Thermal paper fades. A blurry phone photo beats a blank slip in March.

• Download invoices from tools that only show them in a dashboard. Some vendors never email a PDF. Put a monthly reminder to grab those.

If you are VAT or sales tax registered, make sure invoices show the vendor's tax details. Ask your accountant what your country requires on a valid invoice.

Step 6: Run a 30 minute monthly close

This is the habit that holds everything together. Put it on the calendar for the first working day of each month. Close the previous month like this:

1. Import or download bank and card statements for last month (5 minutes).

2. Categorise every line. With rules or a short list, this goes fast after the first two months (10 minutes).

3. Match receipts to every expense line. Mark any missing ones and request them right away (5 minutes).

4. Reconcile your processor. Check that gross minus fees minus refunds equals payouts received (5 minutes).

5. Write down three numbers in a simple log: total cash in, total cash out, and bank balance at month end (2 minutes).

6. Note one thing that surprised you. A tool you forgot about, an API bill that doubled, a refund spike (3 minutes).

That last note is the most valuable part. Over a year, it tells you a story your dashboard never will. If you already keep a lightweight log of why you made product or pricing calls, add the money notes to the same place so you can see decisions and their costs together.

Step 7: Handle annual plans honestly

Annual plans are great for cash. A customer pays $190 today for twelve months. But in your own head, and in many tax systems, that is not all "earned" today. You owe them eleven more months of service.

You do not need full accrual accounting on day one. Do two things:

• Keep a small tab listing each annual customer, the amount, the start date, and months remaining.

• Each month, note how much annual cash is still "owed in service". This is roughly what accountants call deferred revenue.

That stops you from spending January's annual renewals as if they were profit and then wondering why July is tight. Ask your accountant whether your filings need cash basis or accrual basis. Many small businesses can use cash basis for tax, but you still want this note for your own planning. If you are deciding whether to offer annual at all, this Medium piece on putting an annual plan on your pricing page early covers the pricing side.

Step 8: Set money aside for tax

The surprise tax bill is a classic solo founder moment. A simple rule helps: every time you move money to yourself, or once a month, move a fixed percentage of profit into a separate savings account labelled "tax". Your accountant can tell you a sensible percentage for your country and structure. Until then, picking a conservative number and adjusting later is safer than saving nothing.

If you collect sales tax or VAT from customers, that money was never yours. Some founders let their processor or merchant of record handle this. If you collect it yourself, track it in its own line and set it aside in full.

A 14-day setup plan

Common traps

• Logging payouts as revenue. Covered above, but it is the most common mistake by far.

• Too many categories. If you hesitate on a line for more than a few seconds, your list is too long.

• Treating owner transfers as expenses. Money you pay yourself as a sole trader is usually not a business expense. Keep it in its own category and ask your accountant how your structure handles it.

• Forgetting annual renewals. A $240 domain bundle or tool renewal once a year is easy to miss in a monthly mindset. Keep renewal dates on your charges list.

• Skipping two closes in a row. One missed month is fine. Three is how you end up back at the bad weekend. If you skip, do a double close next time, not a perfect one.

• DIY tax filing too early. Organising the books yourself is great. Filing yourself, once there are sales tax, VAT or several countries involved, is where small mistakes get expensive.

Once your books are tidy, you can make better calls about pricing and charging. If you are still at the stage of turning a project into a paid one, the SideHunt playbook on starting to charge for a side project while you have a day job pairs well with this setup.

FAQ

Do I need an accountant if I only make a few hundred dollars a month?

Not every month, but usually once a year for filing, and once at the start to confirm your structure and what you must register for. Clean books keep that bill small.

Is a spreadsheet really enough?

For low volume in one currency, yes. Move to software when categorising takes more than about 20 minutes a month, you add a second currency, or you register for sales tax or VAT.

How far back should I backfill?

At least to the start of the current tax year. If that is too much, start with the last three months so the habit begins now, then backfill a month each weekend.

Should I connect my bank to accounting software?

Usually yes. Bank feeds remove most manual entry. Use read-only connections through the software's official integration, and turn on two-factor login for both the bank and the tool.

Wrapping up

Bookkeeping for a small SaaS is not about being good at finance. It is one account, a short category list, receipts that land in one place, and 30 minutes a month. Do that and you will know your real margin, walk into tax season calm, and have numbers ready when an opportunity shows up. And when you are ready to put your product in front of more people, you can list it on Aura++ and let new users find it while your books quietly stay up to date.