Ok so I have never claimed any tax back on travel ( I work in construction) and have been cards in ( an employee) for the past 5yrs. 2 of which with a company car, no fuel card however. Paper work is limited, p60's, pay slips etc, some fuel receipts, some company travel claims ( documented) at 11p a mile. I know I'm due a rebate of some kind and their are firms who will do it. But who are recommended and what do I need to provide? I know the taxman will be all over me next year, but what it's worth is, well worth it. Travel wise I'm looking at 300 miles a week average, not bothered by commission costs just ease of claim. I have never claimed for anything else either ( washing uniform/ tools expense etc). Cheers.
Save your money - just write a letter to the taxman, detailing your claim.
P87 form. Do one every year to get tax relief on the difference between the mileage we claim and the mileage the tax man allows. As above, write to them and ask how to submit a backdated claim.
Your P60s will indicate what mileage you've claimed at what rate.
Actually, phone them. When filling out a self assessment, I found they were much more helpful over the phone than online.
Normally anything that's a purely business expense would have been just repaid in full (inc VAT) by the company you work for so you're not out of pocket. I don't believe you can personally claim any tax back on those kind of expenses as they are not to your benefit.
However anything that has a benefit in kind element (where you have some personal benefit, say a company car you use for personal use) should be declared on things like a P11D by the company each year and the tax man adjusts your personal tax code as appropriate so you pay more or less tax under PAYE, or may be accounted for on the tax return.
Mileage is a bit different as companies can pay at certain rates, but the GOV allows a benefit at another rate so you may be able to claim a difference, as mentioned above.
As suggested, write to them and say something along the lines of "I've done X miles and been paid 11p/mile [with copies of claims as evidence]. The HMRC approved tax free mileage allowance is 45p/mile so I've paid 36p/mile from my taxed pay, 36p times X miles = £xx so I claim back the tax on this amount". Provided they are genuine business miles there should be no problem.
Edit - the above does not apply when using a company car. The approved rate is much less than 45p as you're not providing the car, it's varied a bit but is probably only about 15p.
It's called mileage allowance relief (MAR). You can claim the tax back on what you get paid (11p) and the revenue approved rate (45p up to 10000 miles, less over that). If you do a self assessment form there's just a single box to enter the amount in, but I presume that they'd want to see some evidence if they decided to audit your return. The first time I got around to claiming it it paid for my Anthem X 1, but that did include a couple of years arrears.
[Edit] don't even think of paying a firm to do it, it really isn't hard.
I'm an accountant and Onzadog is spot on, although your P60's wouldn't normally help. Large claims going back on previous years and HMRC may query them. They now require mileage logs to prove your claims. With your lack of paperwork you may struggle to prove your claim. If your expenses are paid on your payslip then use them as a starting point. Your employer will have the last 6 years payroll data and would be able to supply copies at the worst with a small admin charge. Then back up those expense claims with whatever records you have.