Start-Up Finance Checklist: What to Set Up in Your First 30 Days to Avoid Admin Problems Later
Starting a business is exciting. The first few weeks are usually full of decisions, momentum, and a long to-do list, which makes it very easy to push the finance admin aside and tell yourself you will sort it out later.
The problem is that “later” tends to arrive quickly. By then, you may be dealing with a backlog of receipts, unreconciled bank transactions, missed registrations, and deadlines that now feel much more urgent than they did at the beginning.
The good news is that getting your finances set up properly in the first 30 days is not especially complicated. It just helps to know what to do and in roughly what order. This checklist walks you through the essentials.
Days 1–7: Get the legal and banking basics right
Decide on your structure
One of the first decisions is whether you will operate as a sole trader or through a limited company. That choice affects your tax position, your filing obligations, your record-keeping, and the extent of your personal liability.
For many small start-ups, these are the 2 most common structures. A limited company often gives you more separation between personal and business affairs, but it also brings extra administration. A sole trader structure is usually simpler at the beginning, but there is no legal separation between you and the business. GOV.UK’s step-by-step guide to setting up a limited company confirms that structure affects tax and compliance from the outset.
If you are still weighing this up, our guide on sole trader vs limited company is a good place to start.
Open a dedicated business bank account
This is one of the simplest decisions you can make, and one of the most helpful. Keeping business transactions separate from personal spending makes bookkeeping easier, reduces confusion over expenses, and gives you a much cleaner audit trail from the beginning.
Even where the law does not always force a separate account in every case, it is still one of the most sensible steps you can take in the first week.
Register your business
If you are setting up a limited company, you register it with Companies House. GOV.UK states that when you register online, your company will usually be set up for Corporation Tax at the same time, unless it is dormant. Companies House also says it aims to process most online filings within 24 hours.
If you are operating as a sole trader, you do not incorporate at Companies House, but you do need to register for Self Assessment if you need to file a return. HMRC says you must tell it by 5 October following the end of the relevant tax year if you need to complete a return and have not sent one before.
Getting this done early makes everything else easier.
Days 8–14: Register with HMRC and understand your tax obligations
Corporation Tax
If you have incorporated a company, you must tell HMRC that the company is active for Corporation Tax within 3 months of starting business activity. Starting business activity can include things like buying, selling, advertising, renting property, or employing someone. GOV.UK’s limited company guidance and Corporation Tax registration guidance both make this clear.
Your Corporation Tax payment deadline is usually 9 months and 1 day after the end of your accounting period, while the Company Tax Return is usually due 12 months after the end of the accounting period.
If your early profits are modest, it is also worth understanding the corporation tax small profits rate and how it affects your company.
Self Assessment
If you are a sole trader, Self Assessment is a core part of your tax compliance. If you are a company director, you may also need to file a personal tax return depending on your income and circumstances, for example if you receive dividends, have untaxed income, or HMRC has asked you to file. It is not true that every limited company director automatically has to file one, so it is important to assess your own situation properly. HMRC’s guidance says you should check whether you need to send a return, rather than assume.
VAT
VAT registration is compulsory when your taxable turnover goes over £90,000 in a rolling 12-month period. GOV.UK also confirms that you can choose to register voluntarily below that level. That can make sense for some businesses, especially where customers are themselves VAT-registered and you want to recover VAT on costs.
The right answer depends on your pricing, customers, and margins, so this is a good area to review with an accountant.
Making Tax Digital
Making Tax Digital for VAT is already in force for VAT-registered businesses. Making Tax Digital for Income Tax starts from 6 April 2026 for sole traders and landlords with qualifying income over £50,000. HMRC has confirmed that this rollout begins in phases from that date.
If you want to understand what that means in practice, our guide to Making Tax Digital quarterly update returns is worth reading early.
Days 15–21: Set up your bookkeeping system
This is where many start-ups either build a solid foundation or create problems that take months to unwind.
Choose your accounting software
You can legally keep records in various ways, but cloud accounting software usually makes life much easier once transactions start building up. It helps with bank feeds, invoicing, reconciliations, reporting, and making sure your accountant is working from live and organised data rather than a pile of paperwork.
A xero bookkeeping service can be a very practical way to get that set up properly from the beginning. Our post on Xero bookkeeping basics including chart of accounts and bank feeds is a useful place to start if you are new to it.
If you have already started in spreadsheets, our guide on migrating from spreadsheets to Xero explains how to make the switch.
Understand what counts as an allowable expense
One of the most common early mistakes is not claiming expenses you are entitled to claim because you are not sure what qualifies. Depending on the structure of the business and the nature of the expense, things like software, stationery, certain travel, equipment, broadband, and professional fees may all be relevant.
Our guide on allowable expenses for limited companies is a useful resource to keep handy.
Keep every receipt and record
Discipline here pays off later. HMRC requires self-employed businesses to keep records for at least 5 years after the 31 January submission deadline of the relevant tax year. Limited companies must generally keep company and accounting records for 6 years from the end of the last company financial year they relate to.
That includes invoices, receipts, bank statements, payroll records, and supporting documents. If you get this right from the beginning, your year-end work becomes much easier.
If bookkeeping Nottingham is not something you want to manage yourself, handing it to a specialist early can save time and reduce errors. Our article on why accurate bookkeeping matters for business success explains why this is one of the best early investments a founder can make.
Days 22–30: Payroll, compliance filings, and ongoing processes
Set up payroll if you will be paying salaries
If you are paying yourself a salary through a limited company or employing staff, you need to register as an employer with HMRC before the first payday. GOV.UK says you cannot register more than 2 months before you start paying people, and payroll reporting to HMRC is done on or before each payday.
Payroll mistakes can create problems with tax, National Insurance, and employee records, so it is often worth using a professional payroll service from the outset.
Understand your confirmation statement obligation
If you have a limited company, the confirmation statement is a separate filing from your accounts. Companies House says every company, including dormant and non-trading companies, must file one at least once every year, and you generally have 14 days after the end of the review period to file it.
Our guide on confirmation statements explains what needs to be included and when to file.
Consider whether outsourced finance support makes sense
If the business is moving quickly, or you are already spending too much time on admin instead of revenue-generating work, it may be worth looking at finance outsourcing services rather than trying to do everything yourself or rushing into a full-time hire.
For many early-stage businesses, that can be a sensible way to access experience without taking on the cost of an in-house finance function too early.
If your start-up is property-related
Property businesses often need a little more attention in the first 30 days because the accounting can be more specialised.
If you are launching a letting agency, property management company, or portfolio business, there may be added issues around service charge accounting, client money, trust accounting, and property-specific tax rules.
If your business involves managing buildings, understanding property management accounts early is important. If your focus is investment or letting, accountants for landlords and a specialist property tax advisor can help you avoid mistakes around structure, reporting, and tax treatment.
If you are involved in commercial property, working with a commercial property accountant from the beginning can make the setup cleaner and far easier to manage later.
Getting the structure right before you start buying, letting, or managing property is usually much cheaper than unpicking a poor setup later.
Finding the right accountant for your start-up
You do not necessarily need the biggest firm. You need one that fits your stage and your sector.
For a start-up, it usually helps to find an accountant who:
- Understands early-stage businesses
- Knows your sector
- Is proactive rather than just reactive
- Uses cloud software and can support you with it
- Is clear about pricing and scope from the outset
Working with accountants for start ups means you are more likely to get practical, relevant support instead of generic advice. If you are local, choosing accounting firms in Nottingham can also make it easier to have proper conversations when needed.
Frequently asked questions
Do I need an accountant straight away, or can I wait until year end?
You can legally wait in many cases, but it is rarely the best approach. Early decisions about structure, tax registration, record keeping, and software often have long-term consequences. Getting those right from the start is usually cheaper than fixing them later.
What is the difference between a bookkeeper and an accountant?
A bookkeeper usually handles the day-to-day recording of transactions, reconciliations, and record maintenance. An accountant typically uses that information to prepare accounts, calculate taxes, and provide higher-level advice. Many businesses use both, often through the same firm.
When do I need to register for VAT?
You must register when your taxable turnover exceeds £90,000 in a rolling 12-month period. You can also register voluntarily below that threshold.
Can I run payroll myself?
Technically yes, but it is easy to make errors. HMRC requires reporting on or before payday, and mistakes can affect tax, National Insurance, and workplace pension compliance. For many founders, using payroll support is the more practical option.
What records do I need to keep, and for how long?
Self-employed businesses must generally keep records for at least 5 years after the relevant 31 January deadline, while limited companies must generally keep records for 6 years from the end of the financial year they relate to.
What if I am not sure whether to operate as a sole trader or limited company?
That is one of the most important early decisions. It depends on your income level, sector, risk profile, and growth plans. A good accountant can model both options for your specific situation instead of relying on general assumptions.
Get your start-up finances right from day one
The first 30 days shape everything that follows. Getting your registrations sorted, your bank account opened, your bookkeeping system in place, and your finance support lined up is not over-cautious. It is just good business practice. It reduces the risk of penalties, gives you a clearer view of your finances, and lets you focus more on growing the business.
FHP Accounting works with start-ups and new businesses across Nottingham and nationally, helping founders get properly set up from day one. Whether you are launching as a sole trader or incorporating your first limited company, we can help make sure the financial foundations are solid.
Book a free initial consultation today and let’s get your business started on the right footing.
I lead FHP Accounting, an accountancy practice specialising in Commercial and Residential Property Accounting. Our goal is to make the administration of running property portfolios easier for landlords, managers, and investors — allowing you to focus on what you do best, while we take care of everything behind the scenes.
