Tax prep support
Self assessment preparation support
Finbryn prepares Self Assessment (SA100) returns for directors, sole traders and landlords from your reconciled books, including dividend and director's loan account workpapers, ready for a registered agent to review and file online by 31 January 2027 for the 2025 to 2026 tax year.
Tax working papers
Illustrative client · August 2026
GBP
- Year-end books closed and reconciledDone
- Fixed asset and depreciation scheduleDone
- Book-to-tax adjustments listedDone
- Supporting schedules for the preparerIn progress
- Handed to the signer for review and filingNext
Illustrative. An example of the document, not a client's figures.
Built for directors as much as sole traders
A UK Self Assessment return is not only for the self-employed. Directors who take dividends alongside salary, landlords with rental income, and anyone with untaxed interest or investment income each need one, and we build the workpapers from whichever combination of income sources applies to you, not a template built for sole traders alone.
Dividend and director's loan reconciliation
Where a director takes income as a mix of salary and dividends, we reconcile the dividend voucher trail against the company's own accounts and check the director's loan account balance, since an overdrawn loan account carries its own tax consequences that are easy to miss if the two sets of books are not checked against each other.
The 2025 to 2026 deadlines
The online filing and payment deadline for the 2025 to 2026 tax year is 31 January 2027; anyone filing on paper instead faces an earlier deadline of 31 October 2026. We build toward the earlier date internally so a paper filer is never caught by the shorter window.
Payments on account
If your bill for the year is large enough, HMRC asks for an advance payment toward next year's liability alongside this year's balance, split across two dates. We calculate this alongside the return itself so it is not a surprise addition to the amount you were expecting to pay.
Who reviews and files
We prepare the draft return and its workpapers. A registered agent holding an Agent Services Account, supervised under the UK's money laundering regulations, reviews and files the return with HMRC; landlords and sole traders may also file it themselves once we hand over the completed draft.
Where this fits
This pairs with Making Tax Digital for Income Tax support once your qualifying income crosses the digital reporting threshold, and with monthly bookkeeping to keep dividend and loan records current through the year. See pricing for Self Assessment preparation rates.
Questions
Frequently asked questions: Self assessment preparation support
Do you handle a return with both employment and self-employment income?
Yes. The workpapers are built from whichever combination of income sources applies, not a template for one income type alone.
When is the SA100 due?
31 January 2027 for online filing of the 2025 to 2026 tax year, or 31 October 2026 if you file on paper.
What happens if untaxed interest or dividend income was not reported before?
We include it in the current year's workpapers and flag whether a prior-year disclosure also needs your adviser's attention.
Who files the return, you or a registered agent?
A registered agent under HMRC's money laundering supervision reviews and files it; some landlords and sole traders file the completed draft themselves.
What happens if a payment on account is more than we actually owe?
An overpaid payment on account is credited against the following year's liability or refunded if you request it, so it is not simply lost. We flag when a payment on account looks likely to overstate your actual liability so you can consider requesting a reduction in advance.
Do sole traders need this as well as directors?
Yes, anyone with self-employment, rental, dividend or other untaxed income generally needs a self assessment return.
What is a payment on account?
An advance payment toward next year's tax bill, calculated from this year's liability; we flag it so it is not a surprise.
How do we get started with self assessment preparation support?
Getting started with self assessment preparation support begins with a short review of your current records and software access. Once that is done we confirm scope and timing in writing, and ongoing work begins on the schedule agreed with you.
What if our records for self assessment preparation support are not up to date?
If your records are behind, we scope a catch-up first so self assessment preparation support starts from a clean, reconciled base. That catch-up is priced and timed separately from the ongoing engagement, so you always know what each part costs.
Related services
- Tax prep supportMaking Tax Digital for Income Tax supportPreparation support for the quarterly updates and end-of-period statement required under Making Tax Digital for Income Tax, built from digitally kept records.
- Tax prep supportTax planning supportYear-round planning support that looks ahead of filing season, modeling entity structure, timing and elections so decisions get made before a deadline forces them.
Industries
- Professional servicesBookkeeping for professional service firms such as engineering, architecture and IT consulting billing clients by project or retainer.
- Agencies and consultanciesBookkeeping for marketing agencies, design studios and consulting firms billing clients on retainers and project fees.
- Real estate and property managementBookkeeping for property owners and managers tracking income, expenses and reserves at the level of each individual property.
Next step
Talk to the team that would run your books
A short call covers your setup, your software and what a first month would look like. You get a written scope and price after it.