Changing from cash basis to traditional accounting and back again.

[SusieB]

I have invested £50K in an EIS compliant scheme so have potentially £15K tax relief. The share were distributed 04.04.19. I am liable for approximately £5.7K tax for 18-19 and £5.2 for 17-18. So I can only utilise approximately £10.9K of this tax relief.

I'm a small time landlord and have employment income.

Too try and obtain a bit more of this £15K tax relief is this legitimate and/or possible:

I have a tenant that missed £1300 of rent payment in 18-19. If I changed to traditional accounting for 18-19 I could include these payments he should have made in 18-19. Increasing my liability in 18-19 (when I could get the rebate), and decreasing my liability in 19-20 when he repays me (though he may take longer).

1. Is it a legitimate thing to change to traditional accounting for 18-19, then change back to cash basis from 19-20? Do HMRC mind?

2. I pay all expenses as they happen, so it seems straightforward. Tenants pay monthly in advance. No capital expenses. Do I add the £1300 he should have paid to 18-19 and checked the traditional accounting box. Then tick cash basis in 19-20 and deduct £1300 from the 19-20 profits.

Thank for any help at all.

As a side question, Is there any other way to make use of the remaining tax relief, should I be consulting a tax specialist? Although if possible I need the advice above now for my tax return.