Pursuant to Section 2314 BGB, the beneficiary of the compulsory portion has a right to information from the heirs regarding the existence of the estate. The obligation to provide information in accordance with Section 2314 para. 1 sentence 1 BGB extends to not only to the actual estate, but also to the so-called fictitious estate at the request of the beneficiary of the compulsory portion (BGHZ 89, 24 = NJW 1984, 487). In this context, the fictitious estate includes all gifts subject to offsetting (Section 2315 BGB) and equalisation (Section 2316 BGB), whereby the duty of disclosure with regard to Section 2325 BGB also includes the gifts made by the testator in the last 10 years, including those to the spouse. Not only the gifts expressly designated as gifts must be disclosed, but also other gifts where there is a suspicion of a mixed gift (OLG Frankfurt am Main, judgement of 24 July 2012 - Ref. 11 U 117/10).
The heir has a written inventory of the estate to present the inventory and value of the estate of the deceased. In particular, the list must include the items actually available at the time of inheritance (real estate, bank, securities and custody account balances, company shares, motor vehicles, jewellery, household effects), all liabilities of the estate, all gifts, including gifts of the deceased that are mandatory and gifts of decency, as well as all marriage-related gifts of the deceased to his or her spouse that could be subject to compulsory portion supplementation pursuant to Sections 2325, 2329 BGB (German Civil Code), all gifts that could be subject to compulsory portion supplementation pursuant to Sections 2050 ff, 2316, the matrimonial property regime in which the deceased lived, all contracts in favour of third parties in the event of death and their beneficiaries, all life insurance contracts of the deceased, also insofar as you or third parties are appointed as beneficiaries, the matrimonial property regime in which the deceased lived. This may also include gifts made more than 10 years before the death, for example gifts to the spouse or gifts of items to which the deceased reserved usufruct.
In addition to the right to information, the beneficiary of the compulsory portion has also a valuation claim. In particular with regard to real estate or any company shares of the deceased, the beneficiary of the compulsory portion can demand that the heir obtains an expert opinion on the value.