It seems that it’s hard to find online the other forms of ID DWP will accept.
Firstly, try this Home Office webpage that lists the usual forms of ID the government accepts. The most common being bank statements or previous letters from the DWP or HMRC. These generally need to be dated within the last three months. However, in some instances the Jobcentre has asked for a letter from an employer (or another professional such as a probation worker) to confirm the personal details of the claimant. In Bath we found claimants can use their Bath Resident Card as a form of ID, so if you have a local resident card scheme or something similar, that may be acceptable at your Jobcentre.
However, the most common way Jobcentre Plus complete your ID verification if you do not have a passport or driving licence is to ask five ‘biometric’ questions. There is no list of questions but they are generally around previous benefits you have claimed. You do not need to get all five questions right to pass your ID so do not worry if you do not know the answer to all the questions. (Banks do similar security checks sometimes, asking what date you received money and how much, for example.)
Foreign nationals should also have proof of status that shows they are eligible to claim benefits in the UK, such as documents proving leave to remain, leave to earn, or citizenship of qualifying country (eg, EU).
The government promised an online identity check called Verify but (as of June 2018) it is not working properly. They recognise there is a possible problem that could cause horrible delays but, like the UC system itself, the solutions have been scuppered by IT problems. Keep an eye on https://www.gov.uk/government/publications/introducing-govuk-verify/introducing-govuk-verify and maybe try it out to see if it works for you.
In summary, we have found that the Jobcentre will accept alternatives to the standard forms of ID depending on the circumstances of the person claiming and the area that they live. You should find that there is a workaround you can use. The best step forward is to ask the phone operator about this when you ring to book your ID appointment as they will go through different forms of ID that they accept. If possible, get all this in place (and checked with DWP) before you need to apply for UC as you don’t want this causing delays to your claim.