Every February I see the same thing on social media. Freelancers in Japan photograph a shoebox of crumpled receipts and post “確定申告、地獄” with a crying emoji. I used to be one of them. My first filing as a sole proprietor took three full weekends, and most of that time went on reconstructing things I could have written down in October.

Here’s the uncomfortable truth: the filing window (usually mid-February to mid-March) is when you report your year. October to December is when you can still change it. If you run a guesthouse or freelance in Japan, the next twelve weeks matter more than the filing season itself.

TL;DR

  • October to December is the last window to act on deductions and purchases that count for the 2026 tax year. February is only for reporting.
  • Several useful deductions, including furusato nozei, small business mutual aid (小規模企業共済) and iDeCo contributions, depend on payments made by December 31.
  • Receipts now have to satisfy two separate rule sets: the invoice system (registration numbers) and the electronic bookkeeping law (digital storage rules).
  • The invoice system’s transitional credit for purchases from unregistered suppliers stepped down from 80% to 70% on October 1, 2026. Check how much input credit you can still claim on those purchases.
  • Guesthouse operators should reconcile OTA payouts, accommodation tax remittances and asset start-of-use dates before year-end. Doing it in February is much harder.

Why Start Tax Prep in October Instead of February?

Most of what lowers your tax bill has to happen inside the calendar year. Japanese individual taxation runs January to December. By the time you sit down to file in February, the only thing left is paperwork. A deduction you didn’t pay for, an asset you didn’t put into service, or a receipt you lost can’t be fixed then.

October is also when your numbers for the year are mostly known. Nine months of revenue is enough to estimate taxable income, and that estimate drives almost every decision below.

What Should You Clean Up in Your Receipts Right Now?

Go through every receipt from January to September now and check two things: does it show the issuer’s invoice registration number, and is it stored where you can search it by date, amount and counterparty?

These come from two different laws, and people often mix them up:

  • The invoice system (インボイス制度), since October 2023: if you’re a consumption-tax filer, you need the issuer’s registration number (T + 13 digits) on the receipt to claim the input credit.
  • The electronic bookkeeping law (電子帳簿保存法): receipts you received digitally, such as PDF invoices, Amazon order emails and OTA statements, must be kept digitally. You can’t just print them out. Searchability by date, amount and counterparty is the general rule, but the search-function requirement can be waived if you can respond to tax-office requests to download the data and either your relevant base-period sales are ¥50 million or less, or you keep printouts organized by date and counterparty for presentation.

Paper receipts can be scanned or photographed and stored electronically only if the 電子帳簿保存法 scanner-storage requirements are met. These include image quality, tamper prevention (a timestamp or correction history), output and search requirements. If you miss the timing requirements, you may still need to keep the paper original. As for how long: blue-return (青色申告) record retention is generally seven years for ledgers and key accounting records, but some supporting documents are five years, and consumption-tax invoices and qualified-invoice records can require seven-year retention. Either way, you need years of organized, retrievable records, not a shoebox.

This is the workflow Reshito is designed to support, but the same principle applies if you use accounting software or a spreadsheet: catching up in October is far easier than in February.

Which Deductions Have a December 31 Deadline?

The main deductions that depend on year-end timing are furusato nozei donations, small business mutual aid (小規模企業共済) contributions, iDeCo contributions, and business expenses you actually incur within the year.

A few notes from my own experience:

  • Furusato nozei: your income for the year sets your cap, so October is a good time to estimate it. If you file a tax return, you claim all your furusato nozei donations on the return instead of using the “one-stop” special rule. The one-stop rule is for people who generally don’t need to file a return and donate to no more than five municipalities.
  • 小規模企業共済: only amounts actually paid or debited by year-end count for that year. If you want a late-year increase or prepayment to count, confirm the cash/prepayment procedure and deadline with 中小機構 (SMRJ) or the financial institution that handles your account. Account debits that happen in January count for the following year.
  • Business expenses: an expense counts in the year it’s incurred, not the year you pay the card bill. Don’t buy things you don’t need just to cut tax, though. Spending ¥100,000 to save ¥20,000 of tax is still spending ¥80,000.

I wrote separate posts on furusato nozei and 小規模企業共済 if you want the details.

Is the Invoice System Changing This Autumn?

Yes. The invoice system was introduced with transitional measures that phase in over several years, and the first step-down took effect on October 1, 2026, three years after the system began.

Two to check with your accountant:

  1. Input credit on purchases from unregistered suppliers. Under the current schedule, you could claim 80% of the consumption tax on purchases from unregistered suppliers through September 30, 2026. It’s 70% from October 1, 2026 for two years, 50% from October 1, 2028 for two years, and 30% from October 1, 2030 for one year. From October 1, 2031 there is no credit at all. The National Tax Agency also notes a cap: the transitional measure covers at most ¥100 million of purchases per unregistered supplier per year (or business year). If you rely on small, unregistered cleaners, handymen or local suppliers, your cost base may quietly go up.
  2. The simplified “20% special rule” (2割特例) for businesses that registered as invoice issuers when they otherwise wouldn’t have had to. If you’re an eligible calendar-year sole proprietor, it generally remains available for your 2026 consumption-tax return. For the 2027 and 2028 returns, the National Tax Agency now describes a “30% special rule” (3割特例) for eligible individual businesses.

These figures come from the 2026 tax reform, and these measures have been adjusted before, so confirm the details for your situation with the National Tax Agency or your 税理士.

What About Big Purchases You’re Planning?

If you’re planning to buy equipment, furniture or renovations anyway, timing matters. Depreciation starts when an asset is put into service, not when you order it.

For guesthouse operators this trips people up every year. A new air conditioner bought on December 20 but installed on January 8 belongs to next year. Qualifying blue-return taxpayers can also use the small-asset exception. For assets acquired on or after April 1, 2026 and before March 31, 2029, items costing at least ¥100,000 but less than ¥400,000 can be expensed in full in the year they’re put into use, up to ¥3 million in total per year. Conditions apply, so check them before relying on it.

What Should Guesthouse Operators Check Specifically?

On top of the general freelancer list, short-term rental operators have three reconciliations that get much harder if you leave them until February:

  • OTA payouts against bookings. Airbnb, Booking.com and the others pay out on different schedules and deduct commission in different ways. A stay in late December may pay out in January. Decide now how you’re recognising revenue and apply it the same way across platforms.
  • Accommodation tax collected against remitted. If you operate in a city with 宿泊税, make sure what you collected matches what you remitted. The rules vary a lot by city: some charge a flat rate, others use price bands.
  • Gross against net. Year-end is a good moment to work out your actual net yield after OTA fees, cleaning, utilities, consumables and 固定資産税. Many small properties lose a large share of revenue to operating costs before debt service, so calculate your own net yield from your actual books.

My Own Q4 Routine

My routine is simple. In the first week of October I block one afternoon to catch up on receipts and estimate my income for the year. In mid-November I do a second pass, make my furusato nozei donations and finalise any planned purchases. In mid-December I do a last check that nothing is half-installed or unpaid. When February comes, filing takes an evening rather than three weekends.

It isn’t glamorous, but it’s one of the most cost-effective tax habits I know.

FAQ

Q: When is the 確定申告 filing period for the 2026 tax year?

For 2026 income tax, the National Tax Agency lists March 15, 2027 as the filing and payment deadline. Tax-office consultations and return acceptance start on February 16, 2027.

Q: Can I just keep paper printouts of PDF invoices I received by email?

Generally no. Under the electronic bookkeeping law, documents you received electronically must be kept electronically. Searchability by date, amount and counterparty is the general rule, though the search requirement can be waived for smaller businesses that meet certain conditions. Paper receipts, on the other hand, can be scanned or photographed and stored digitally if the scanner-storage requirements are met.

Q: Do I need to worry about the invoice system if I’m not registered as a consumption-tax filer?

Your own filing may not change, but your business customers can lose part of their input credit when they pay you. That can come up in price negotiations, especially as the transitional measures step down.

This post is for informational purposes only and does not constitute legal or tax advice. Please consult a qualified professional for your specific situation.