How-to guide: Self Assessment Portal

Filing your Self Assessment with Finmo is a simple step-by-step process which this article guides you seamlessly through every stage of your tax return. 

Finmo is fully digital with no need to create spreadsheets or manually count expense receipts, It’s all done online. Prior to submission, an expert accountant will review your return and make sure you feel confident at every stage. 


It’s important to get your ducks in a row before you start the Self Assessment process. Whether it’s understanding the right dates or the steps you will need to go through before you can start your Self Assessment, you can check out our article on How to file your Self Assessment and pay your tax bill

Getting your head around business expenses can be a tough nut to crack. Especially when there are so many grey areas. Now’s the time to do your research – our blog, Business expenses explained for the self employed, is a good place to start. 

Don’t forget you can also get advice from our bookkeepers if you decide to do your Self Assessment through Finmo. 

Filling in your Self Assessment with Finmo

Once you’ve purchased one of our Plans, it’s now time to start filling in your Self Assessment through the Finmo web portal. To do so:

  1. Log in to the Finmo web portal >.
  2. Click Self Assessment on the navigation bar.
  3. You’ll then be guided through a series of forms where you’ll enter information about your work, income and business expenses. You’ll be taken through the following easy-to-navigate sections:

Overview (1-2 minutes) 

Make sure we have all the relevant profile information (this is the stuff that’s not related to transactions).

Income (5-7 minutes) 

  1. Review your income

For every job you have, review the income added to the Finmo app or portal and make sure each income transaction is allocated to the appropriate job.

If you haven’t downloaded the app, you can quickly and easily add your income within the Transactions section of the portal.

      2. Answer some questions about your income throughout the year. 

You’ll be asked specific questions about the different sources of income and how much you’ve made via each source over the course of the year. 

If one source of income (a job) is from an employer and you’re paid through PAYE, you’ll enter information from a P45 or P60, and possibly a P11D form. You’d have received these from your employer where relevant. 

If you have multiple jobs/sources of income (e.g. rental plus self-employment or PAYE plus self-employment), you‘ll have to go through this exercise for each of your jobs.

Expenses (5-15 minutes)

  1. Review your expenses

For each job, you’ll need to review your expenses, making sure your transactions are correctly tagged. Only expenses related to a particular job should be tagged as such. 

Using Finmo to track and tag these expenses should be much easier than your usual process. It’s important to make sure your expenses are accurate so you don’t pay any more or less tax than you should. This is when you can pick the brains of a dedicated Finmo expert. 

If you want to import your expenses from a spreadsheet or other form of tracer, we can do that for you. Since this is something we have to do manually, we need to charge for our time, but it’s only £25 + vat. Email us at

      2. Answer some questions about your expenses throughout the year. 

Our questions in this section range from asking about travelling for work to detailing your work from home situation. We’ve written educational pieces about these types of expenses in our Self Employed Expenses section.

If you have multiple jobs/sources of income (e.g. rental plus self-employment or PAYE plus self-employment), you‘ll have to complete the questions section for each job. 

Tax Relief (1-3 minutes) 

Review and enter information about non-business related tax relief items, like pensions, student loans and charity giving. We make sure to ask you relevant questions to ensure you don’t miss anything!

Documents (2-3 minutes) 

Depending on the answers to the previous sections, we may ask you for specific documents. Documents that everyone needs to upload are proof of ID and proof of address, as well as any supporting documents for your income and expenses. 

For example, If you have a job that paid you through PAYE, then this is where you would upload a copy of your P60 or P45. 

Review your Self Assessment with a Finmo Accountant 

This is an important part of the process. When you complete a Self Assessment with Finmo, you’ll get your Self Assessment thoroughly reviewed by a bookkeeper and accountant. They’ll provide you with feedback and point out areas where you might save money.

Finmo Lite and Complete packages

For those with our Lite and Complete packages, you’ll receive a full accountant review of your Self Assessment, with written feedback via email plus a telephone consultation with your bookkeeper, if needed.

Finmo Bookkeeper package

For those with our Bookkeeper package, when your books are ready your bookkeeper will prepare your tax return and file it for you. Allowing you to focus on your business without the worry and time spent getting your tax return right.

Check out our Pricing plans to find out more, and please do get in touch if you have any questions.

Sign and submit

After you’ve made all necessary changes to your Self Assessment and are happy with it, we’ll ask you to digitally sign it before we submit it on your behalf.

Voila – you’re done! No more doubting whether you’ve done things correctly or paying over the odds for an accountant. No more tax-induced headaches or wasting money paying too much tax. 

Just simple, time and money-efficient tax filing with confidence. Sorted.