Learn how to prepare for your first Self Assessment tax return with a simple checklist of key papers, income records and expense details. Getting organised early helps you file faster, avoid errors and meet HMRC deadlines without the stress of chasing missing documents.

1. What to Prepare Before Filing Your First Self Assessment
The first time you sit down to file a Self Assessment tax return, it is not
the tax form that slows you down, it is the missing paperwork. HMRC
will expect proof of your income, expenses and other financial details,
and if you do not have them ready you will be chasing documents
instead of filling in boxes. Getting organised at the start means fewer
mistakes and a faster submission. If you need a step-by-step guide to the
process of filing self assessment tax return, our First Time Filer’s Guide
to Self Assessment Tax Returns covers that in detail.
Here is a quick checklist of what to gather before completing your online
Self Assessment form.
Personal details
• Unique Taxpayer Reference (UTR)
• National Insurance number
• Government Gateway user ID and password

2. Income records
• P60 or P45 from any employers
• Payslips if you need to cross-check figures
• Invoices and receipts if you are self-employed
• Bank statements showing business income
• Details of rental income, dividends or interest received
Expense records
• Receipts for business travel and mileage logs
• Home office costs if you work from home
• Records for equipment and office supplies
• Professional fees and subscription costs
Other financial information
• Pension contribution statements
• Gift Aid donation receipts for charities
• Student loan statements if repayments are due
• Capital gains records if you have sold shares, property or other
assets
Helpful tips
• Keep all documents in one labelled folder, either physical or digital
• Sort records by tax year for easy reference
• Check figures against your bank statements before submitting
• File your return early to avoid last-minute errors and stress
Getting your paperwork together before starting your Self Assessment
tax return means the process will be faster and more accurate. Once
everything on this list is ready, you can move on to completing your
return using the guidance in our First Time Filer’s Guide to Self
Assessment Tax Returns.