Setting Up Your MTD Bookkeeping System: A Practical 75-Day Guide

With 75 days until the Q1 deadline on 7 August, many sole traders and landlords still haven't set up proper record keeping for Making Tax Digital. If you're reading this in late May, you're not alone - but you do need to act now. This guide walks through the practical decisions you need to make: spreadsheet versus software, what to capture for each transaction, how often to reconcile, and keeping everything HMRC-ready.

The good news? 75 days is plenty of time to get organised. The key is making the right choices upfront rather than scrambling in July and hoping for the best.

The Foundation: What HMRC Actually Needs

Before diving into systems and software, let's be clear about what you're tracking for. HMRC requires digital records that capture your income and allowable expenses with enough detail to support your quarterly updates.

For each transaction, you need:

• Date
• Amount
• Description (what it was for)
• Category (type of income or expense)
• VAT amount (if VAT registered)

That's it. You don't need complex project tracking, customer relationship management, or inventory systems. Focus on these basics and you'll meet HMRC's requirements. Our guide on what HMRC actually needs for Q1 covers the specifics in more detail.

Decision 1: Spreadsheet or Software?

Your first major decision is whether to use spreadsheets or dedicated MTD software. Both can work, but they suit different situations.

Spreadsheets Work When

• You have fewer than 50 transactions per quarter
• You're comfortable with Excel or Google Sheets
• Your income sources are straightforward
• You don't mind manual data entry
• You use bridging software to submit to HMRC

A simple spreadsheet with columns for date, description, income, and expenses can handle most sole trader and landlord needs. The key is consistency - use the same categories every time and keep everything in one place.

Software Makes Sense When

• You have more than 50 transactions per quarter
• You want bank feed integration
• You need automated categorisation
• You want built-in HMRC submission
• Multiple income types complicate your records

Our practical guide to choosing MTD software covers the options in detail. For most people, simple software or bridging software handles the job without the complexity of full accounting packages.

Decision 2: What to Track Per Transaction

Here's where many people overthink things. You need enough detail to satisfy HMRC, but you don't need to track every possible data point.

Essential Fields

Date: When the transaction happened (not when you recorded it).

Description: Clear enough that you'll understand it in six months. "Coffee with client" is better than just "coffee".

Amount: The actual figure - gross for income, net for expenses if you're VAT registered.

Category: Match these to the categories in your quarterly update. Don't create dozens of subcategories - HMRC only needs broad groupings.

Optional but Useful Fields

Reference: Invoice numbers, receipt numbers, or your own transaction codes.

Bank account: If you use multiple accounts, track which one each transaction uses.

VAT rate: Essential if VAT registered, irrelevant if not.

Client/tenant: Useful for your own management but not required for HMRC.

Decision 3: Income Categories That Matter

Your quarterly updates group income into specific categories. Set up your tracking system to match these from day one rather than trying to reorganise later.

The main categories are:

• Business income: Sales, fees, commission - your main trading income
• Property income: Rent, deposits kept, service charges recovered
• Other income: Interest, dividends, casual income

Some income types don't go in quarterly updates at all. Our guide to what income types MTD accepts explains what goes where and what you'll handle differently.

The key is consistency. If you categorise something as business income in Q1, use the same category in Q2. Don't switch between "consultancy fees" and "professional services" for the same type of work.

Decision 4: Expense Tracking Strategy

Allowable expenses reduce your tax bill, so good tracking here directly saves money. But you need to track things HMRC will actually accept.

Common Allowable Expenses

• Office costs (rent, utilities, phone)
• Travel (business journeys, not commuting)
• Professional fees (accountant, solicitor, subscriptions)
• Marketing (website, advertising, networking)
• Equipment (computers, tools, furniture)
• Insurance (professional, public liability)

For landlords, add:

• Property maintenance and repairs
• Letting agent fees
• Ground rent and service charges
• Safety certificates and inspections

Our comprehensive guide to allowable expenses covers what you can and can't claim in detail.

The Receipt Question

You need evidence for every expense you claim. This doesn't always mean paper receipts - bank statements, email confirmations, and digital receipts all count. But you need something that shows:

• What you bought
• When you bought it
• How much you paid
• Who you paid

Take photos of paper receipts and store them digitally. Thermal paper receipts fade, and you'll need records for at least five years after the tax year ends.

Decision 5: How Often to Update Your Records

HMRC doesn't specify how often you update your records, but practical experience suggests clear patterns work best.

Weekly Updates Work Well When

• You have regular, predictable income
• Most expenses go on business cards or accounts
• You want to stay on top of your finances

Spending 30 minutes every Friday updating records keeps everything current and makes quarterly updates straightforward.

Monthly Updates Suit

• Irregular income patterns
• Fewer transactions overall
• People who prefer batch processing

Monthly updates align well with bank statement cycles and give you regular financial snapshots.

Avoid Daily or Quarterly

Daily updates usually become a chore you skip. Quarterly updates mean everything gets crammed into deadline periods when you're already stressed.

Decision 6: Bank Reconciliation Approach

Bank reconciliation means making sure your records match your actual bank accounts. This catches missing transactions, duplicate entries, and banking errors.

For simple businesses, reconciliation can be straightforward:

1. List all income in your records for the period
2. Add up all expenses in your records for the period
3. Check these against your bank statement
4. Investigate any differences

Common Reconciliation Issues

Timing differences: You invoice in May, but payment arrives in June. Record based on when the money actually moved.

Bank charges: Often overlooked but they're allowable business expenses.

Personal transactions: If you use business accounts for personal spending, don't include these in your business records.

Cash transactions: Harder to track but just as important. Keep cash receipts and record them promptly.

Your 75-Day Implementation Timeline

Here's a practical timeline to get everything working in the next 75 days:

Week 1 (Days 1-7): Foundation

• Choose your recording system (spreadsheet or software)
• Set up your categories to match HMRC requirements
• Gather all financial records from 6 April onwards
• Create your filing system for receipts and documents

Week 2-3 (Days 8-21): Data Entry

• Enter all transactions from 6 April to current date
• Reconcile against bank statements
• Identify any missing receipts or documentation
• Set up your regular update schedule

Week 4-8 (Days 22-56): Regular Operations

• Follow your chosen update frequency
• Test your system with real data
• Adjust categories or processes if needed
• Practice reconciliation routines

Week 9-10 (Days 57-70): Pre-Submission Preparation

• Complete final reconciliation for Q1 period
• Review all categories and classifications
• Prepare your quarterly update figures
• Check everything against our pre-submission checklist

Final Week (Days 71-75): Buffer Time

• Handle any last-minute issues
• Submit your Q1 quarterly update
• Document what worked well for Q2

Common Setup Mistakes to Avoid

Having helped thousands of sole traders and landlords set up MTD systems, we see the same mistakes repeatedly:

Over-complicating categories: You don't need separate categories for "office pens" and "office paper". "Office supplies" covers both.

Mixing business and personal: Use separate accounts if possible, or at least separate records if not.

Ignoring timing: Record transactions when they happen, not when you remember to enter them.

Poor backup habits: Keep copies of your records. Cloud storage, external drives, or both.

Perfectionism paralysis: A working system you actually use beats a perfect system you abandon after two weeks.

Our guide to Q1 tracking mistakes covers these issues in more detail.

Keeping Records HMRC-Ready

HMRC can ask to see your records up to five years after the tax year ends. This means your system needs to be sustainable long-term, not just good enough for Q1.

Storage Requirements

• Keep all records for at least five years after 31 January following the tax year
• Store them in a format you can still access in five years
• Include supporting documents (receipts, invoices, contracts)
• Make sure someone else can understand your system if needed

Audit Trail Basics

If HMRC queries your figures, you need to show how you arrived at them. This means:

• Clear links between source documents and recorded figures
• Obvious categorisation logic
• Reconciliation working papers
• Notes explaining unusual transactions

You don't need professional accounting standards, but you do need clarity and consistency.

Planning Beyond Q1

Your Q1 system should work for the whole tax year. That means thinking about Q2 (due 7 November), Q3 (due 7 February), and Q4 (due 7 May) when you set things up now.

The quarterly cycle becomes routine once you establish good habits. Each quarter follows the same pattern: update records, reconcile accounts, prepare figures, submit update. The difference between quarterly updates and your final declaration is mainly timing and detail level.

With 75 days until the Q1 deadline, you have enough time to build a system that works long-term. Focus on simplicity, consistency, and meeting HMRC's actual requirements rather than creating the perfect bookkeeping system. Get started this week, stick to your chosen approach, and you'll find the August deadline much less stressful than you expected.